false

0000722574

Dec. 31, 2024

Fidelity Advisor® Mid Cap II Fund Class Z

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains information about Fidelity Advisor® Mid Cap II Fund for the period January 1, 2024 to December 31, 2024.

Additional Information [Text Block]

You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

Additional Information Phone Number

1-877-208-0098

Additional Information Website

fundresearch.fidelity.com/prospectus/sec

Expenses Paid, Amount

$ 63

Factors Affecting Performance [Text Block]

What affected the Fund's performance this period?

•U.S. equities gained in 2024, driven by a sturdy economy, the Federal Reserve's long-anticipated pivot to cutting interest rates and the potential for artificial intelligence to drive transformative change.

•Against this backdrop, security selection was the primary contributor to the fund's performance versus the S&P MidCap 400 Index for the year, led by the consumer discretionary sector. Stock picks in consumer staples and financials also boosted the fund's relative performance.

•The top individual relative contributor was our non-benchmark stake in Vertiv Holdings (+142%). This period we decreased our stake in the stock. An overweight in Deckers Outdoor (+81%) helped as well. We decreased our position in 2024. A non-benchmark holding in Howmet Aerospace gained 112% and further bolstered the fund's result. The stock was not held at period end.

•In contrast, the biggest detractor from performance versus the benchmark was stock picking in information technology. Also hurting our result was security selection in energy and utilities. Lastly, the fund's position in cash also detracted.

•Not owning Texas Pacific Land, a benchmark component that gained 117%, was the largest individual relative detractor. A stake in Super Micro Computer (+276%) also hurt. The stock was not held at period end. Another notable relative detractor was our position in Emcor (+111%), an investment we established this period.

•Notable changes in positioning include higher allocations to the health care and financials sectors.

Line Graph [Table Text Block]

How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE December 31, 2014 through December 31, 2024. Initial investment of $10,000. Class Z $10,000 $9,862 $11,052 $13,341 $11,375 $14,086 $16,741 $20,989 $17,909 $20,627 $24,206 S&P MidCap 400® Index $10,000 $9,782 $11,811 $13,730 $12,208 $15,407 $17,511 $21,847 $18,993 $22,115 $25,196 Russell 3000® Index $10,000 $10,048 $11,327 $13,721 $13,002 $17,035 $20,593 $25,877 $20,907 $26,334 $32,604 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Holdings Count | shares

180

Investment Company Portfolio Turnover

52.00%

Holdings [Text Block]

MARKET SECTORS (% of Fund's net assets) Financials 20.1 Industrials 18.0 Consumer Discretionary 12.3 Health Care 11.7 Information Technology 9.8 Real Estate 6.5 Energy 6.0 Materials 5.2 Consumer Staples 4.9 Utilities 3.4 Communication Services 1.8 Common Stocks 99.7 Short-Term Investments and Net Other Assets (Liabilities) 0.3 ASSET ALLOCATION (% of Fund's net assets) Common Stocks - 99.7 Short-Term Investments and Net Other Assets (Liabilities) - 0.3 United States 91.1 Canada 2.2 Israel 1.6 United Kingdom 1.6 Belgium 0.9 Puerto Rico 0.8 Brazil 0.4 Italy 0.4 France 0.3 Others 0.7 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) United States - 91.1 Canada - 2.2 Israel - 1.6 United Kingdom - 1.6 Belgium - 0.9 Puerto Rico - 0.8 Brazil - 0.4 Italy - 0.4 France - 0.3 Others - 0.7

Material Fund Change [Text Block]

How has the Fund changed?

This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's next prospectus, which we expect to be available by March 1, 2025 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's next prospectus, which we expect to be available by March 1, 2025 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

Updated Prospectus Email Address

fidfunddocuments@fidelity.com

Fund Name

Fidelity Advisor® Mid Cap II Fund

Trading Symbol

FIICX

Shareholder Report Annual or Semi-Annual

annual shareholder report

Material Fund Change Notice [Text Block]

This report describes changes to the Fund that occurred during the reporting period.

Additional Information Email

fidfunddocuments@fidelity.com

Expenses [Text Block]

What were your Fund costs for the last year?

(based on hypothetical $10,000 investment)

FUND COST (PREVIOUS YEAR)

	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class C	$ 185	1.71%

Expense Ratio, Percent

1.71%

Performance Past Does Not Indicate Future [Text]

The Fund's past performance is not a good predictor of the Fund's future performance.

Average Annual Return [Table Text Block]

AVERAGE ANNUAL TOTAL RETURNS: 1 Year 5 Year 10 Year Class C (incl. contingent deferred sales charge) 15.08% 10.11% 8.11% Class C 16.08% 10.11% 8.11% S&P MidCap 400® Index 13.93% 10.34% 9.68% Russell 3000® Index 23.81% 13.86% 12.55% Visit institutional.fidelity.com for more recent performance information. The Fund's past performance is not a good predictor of the Fund's future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Net Assets

$ 1,551,980,039

Advisory Fees Paid, Amount

$ 9,939,485

Additional Fund Statistics [Text Block]

Key Fund Statistics

(as of December 31, 2024)

KEY FACTS
Fund Size	$1,551,980,039
Number of Holdings	180
Total Advisory Fee	$9,939,485
Portfolio Turnover	52%

Largest Holdings [Text Block]

TOP HOLDINGS (% of Fund's net assets) US Foods Holding Corp 1.5 Reinsurance Group of America Inc 1.4 East West Bancorp Inc 1.4 ITT Inc 1.3 Williams-Sonoma Inc 1.3 Wintrust Financial Corp 1.3 Performance Food Group Co 1.2 Primerica Inc 1.2 AptarGroup Inc 1.2 Wix.com Ltd 1.2 13.0

Material Fund Change Expenses [Text Block]

The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes:

Management fee
Operating expenses

The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.

Updated Prospectus Phone Number

1-877-208-0098

Updated Prospectus Web Address

fundresearch.fidelity.com/prospectus/sec

Shareholder Report [Line Items]

Class Name

Fidelity Advisor® Mid Cap II Fund Class A

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains information about Fidelity Advisor® Mid Cap II Fund for the period January 1, 2024 to December 31, 2024.

Additional Information [Text Block]

You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

Additional Information Phone Number

1-877-208-0098

Additional Information Website

fundresearch.fidelity.com/prospectus/sec

Expenses Paid, Amount

$ 105

Factors Affecting Performance [Text Block]

What affected the Fund's performance this period?

•U.S. equities gained in 2024, driven by a sturdy economy, the Federal Reserve's long-anticipated pivot to cutting interest rates and the potential for artificial intelligence to drive transformative change.

•Against this backdrop, security selection was the primary contributor to the fund's performance versus the S&P MidCap 400 Index for the year, led by the consumer discretionary sector. Stock picks in consumer staples and financials also boosted the fund's relative performance.

•The top individual relative contributor was our non-benchmark stake in Vertiv Holdings (+142%). This period we decreased our stake in the stock. An overweight in Deckers Outdoor (+81%) helped as well. We decreased our position in 2024. A non-benchmark holding in Howmet Aerospace gained 112% and further bolstered the fund's result. The stock was not held at period end.

•In contrast, the biggest detractor from performance versus the benchmark was stock picking in information technology. Also hurting our result was security selection in energy and utilities. Lastly, the fund's position in cash also detracted.

•Not owning Texas Pacific Land, a benchmark component that gained 117%, was the largest individual relative detractor. A stake in Super Micro Computer (+276%) also hurt. The stock was not held at period end. Another notable relative detractor was our position in Emcor (+111%), an investment we established this period.

•Notable changes in positioning include higher allocations to the health care and financials sectors.

Line Graph [Table Text Block]

How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE December 31, 2014 through December 31, 2024. Initial investment of $10,000 and the current sales charge was paid. Class A $9,425 $9,251 $10,324 $12,414 $10,540 $12,997 $15,381 $19,214 $16,328 $18,729 $21,898 S&P MidCap 400® Index $10,000 $9,782 $11,811 $13,730 $12,208 $15,407 $17,511 $21,847 $18,993 $22,115 $25,196 Russell 3000® Index $10,000 $10,048 $11,327 $13,721 $13,002 $17,035 $20,593 $25,877 $20,907 $26,334 $32,604 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Holdings Count | shares

180

Investment Company Portfolio Turnover

52.00%

Holdings [Text Block]

MARKET SECTORS (% of Fund's net assets) Financials 20.1 Industrials 18.0 Consumer Discretionary 12.3 Health Care 11.7 Information Technology 9.8 Real Estate 6.5 Energy 6.0 Materials 5.2 Consumer Staples 4.9 Utilities 3.4 Communication Services 1.8 Common Stocks 99.7 Short-Term Investments and Net Other Assets (Liabilities) 0.3 ASSET ALLOCATION (% of Fund's net assets) Common Stocks - 99.7 Short-Term Investments and Net Other Assets (Liabilities) - 0.3 United States 91.1 Canada 2.2 Israel 1.6 United Kingdom 1.6 Belgium 0.9 Puerto Rico 0.8 Brazil 0.4 Italy 0.4 France 0.3 Others 0.7 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) United States - 91.1 Canada - 2.2 Israel - 1.6 United Kingdom - 1.6 Belgium - 0.9 Puerto Rico - 0.8 Brazil - 0.4 Italy - 0.4 France - 0.3 Others - 0.7

Material Fund Change [Text Block]

How has the Fund changed?

This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's next prospectus, which we expect to be available by March 1, 2025 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's next prospectus, which we expect to be available by March 1, 2025 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

Updated Prospectus Email Address

fidfunddocuments@fidelity.com

Fund Name

Fidelity Advisor® Mid Cap II Fund

Trading Symbol

FITIX

Shareholder Report Annual or Semi-Annual

annual shareholder report

Material Fund Change Notice [Text Block]

This report describes changes to the Fund that occurred during the reporting period.

Additional Information Email

fidfunddocuments@fidelity.com

Expenses [Text Block]

What were your Fund costs for the last year?

(based on hypothetical $10,000 investment)

FUND COST (PREVIOUS YEAR)

	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class M	$ 131	1.21%

Expense Ratio, Percent

1.21%

Performance Past Does Not Indicate Future [Text]

The Fund's past performance is not a good predictor of the Fund's future performance.

Average Annual Return [Table Text Block]

AVERAGE ANNUAL TOTAL RETURNS: 1 Year 5 Year 10 Year Class M (incl. 3.50% sales charge) 12.51% 9.93% 8.15% Class M (without 3.50% sales charge) 16.59% 10.72% 8.53% S&P MidCap 400® Index 13.93% 10.34% 9.68% Russell 3000® Index 23.81% 13.86% 12.55% Visit institutional.fidelity.com for more recent performance information. The Fund's past performance is not a good predictor of the Fund's future performance. The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Net Assets

$ 1,551,980,039

Advisory Fees Paid, Amount

$ 9,939,485

Additional Fund Statistics [Text Block]

Key Fund Statistics

(as of December 31, 2024)

KEY FACTS
Fund Size	$1,551,980,039
Number of Holdings	180
Total Advisory Fee	$9,939,485
Portfolio Turnover	52%

Largest Holdings [Text Block]

TOP HOLDINGS (% of Fund's net assets) US Foods Holding Corp 1.5 Reinsurance Group of America Inc 1.4 East West Bancorp Inc 1.4 ITT Inc 1.3 Williams-Sonoma Inc 1.3 Wintrust Financial Corp 1.3 Performance Food Group Co 1.2 Primerica Inc 1.2 AptarGroup Inc 1.2 Wix.com Ltd 1.2 13.0

Material Fund Change Expenses [Text Block]

The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.

Updated Prospectus Phone Number

1-877-208-0098

Updated Prospectus Web Address

fundresearch.fidelity.com/prospectus/sec

Shareholder Report [Line Items]

Class Name

Fidelity Advisor® Mid Cap II Fund Class I

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains information about Fidelity Advisor® Mid Cap II Fund for the period January 1, 2024 to December 31, 2024.

Additional Information [Text Block]

You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

Additional Information Phone Number

1-877-208-0098

Additional Information Website

fundresearch.fidelity.com/prospectus/sec

Expenses Paid, Amount

$ 77

Factors Affecting Performance [Text Block]

What affected the Fund's performance this period?

•U.S. equities gained in 2024, driven by a sturdy economy, the Federal Reserve's long-anticipated pivot to cutting interest rates and the potential for artificial intelligence to drive transformative change.

•Against this backdrop, security selection was the primary contributor to the fund's performance versus the S&P MidCap 400 Index for the year, led by the consumer discretionary sector. Stock picks in consumer staples and financials also boosted the fund's relative performance.

•The top individual relative contributor was our non-benchmark stake in Vertiv Holdings (+142%). This period we decreased our stake in the stock. An overweight in Deckers Outdoor (+81%) helped as well. We decreased our position in 2024. A non-benchmark holding in Howmet Aerospace gained 112% and further bolstered the fund's result. The stock was not held at period end.

•In contrast, the biggest detractor from performance versus the benchmark was stock picking in information technology. Also hurting our result was security selection in energy and utilities. Lastly, the fund's position in cash also detracted.

•Not owning Texas Pacific Land, a benchmark component that gained 117%, was the largest individual relative detractor. A stake in Super Micro Computer (+276%) also hurt. The stock was not held at period end. Another notable relative detractor was our position in Emcor (+111%), an investment we established this period.

•Notable changes in positioning include higher allocations to the health care and financials sectors.

Line Graph [Table Text Block]

How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE December 31, 2014 through December 31, 2024. Initial investment of $10,000. Class I $10,000 $9,848 $11,020 $13,285 $11,319 $13,995 $16,609 $20,801 $17,728 $20,392 $23,894 S&P MidCap 400® Index $10,000 $9,782 $11,811 $13,730 $12,208 $15,407 $17,511 $21,847 $18,993 $22,115 $25,196 Russell 3000® Index $10,000 $10,048 $11,327 $13,721 $13,002 $17,035 $20,593 $25,877 $20,907 $26,334 $32,604 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Holdings Count | shares

180

Investment Company Portfolio Turnover

52.00%

Holdings [Text Block]

MARKET SECTORS (% of Fund's net assets) Financials 20.1 Industrials 18.0 Consumer Discretionary 12.3 Health Care 11.7 Information Technology 9.8 Real Estate 6.5 Energy 6.0 Materials 5.2 Consumer Staples 4.9 Utilities 3.4 Communication Services 1.8 Common Stocks 99.7 Short-Term Investments and Net Other Assets (Liabilities) 0.3 ASSET ALLOCATION (% of Fund's net assets) Common Stocks - 99.7 Short-Term Investments and Net Other Assets (Liabilities) - 0.3 United States 91.1 Canada 2.2 Israel 1.6 United Kingdom 1.6 Belgium 0.9 Puerto Rico 0.8 Brazil 0.4 Italy 0.4 France 0.3 Others 0.7 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) United States - 91.1 Canada - 2.2 Israel - 1.6 United Kingdom - 1.6 Belgium - 0.9 Puerto Rico - 0.8 Brazil - 0.4 Italy - 0.4 France - 0.3 Others - 0.7

Material Fund Change [Text Block]

How has the Fund changed?

This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's next prospectus, which we expect to be available by March 1, 2025 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund since January 1, 2024. For more complete information, you may review the Fund's next prospectus, which we expect to be available by March 1, 2025 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.

Updated Prospectus Email Address

fidfunddocuments@fidelity.com