In 2014, the Company adopted a stock compensation plan (the "2014 Equity Incentive Plan") pursuant to which the Company may grant stock options, stock purchase rights, restricted stock awards, or stock awards to employees, directors and consultants (including prospective employees, directors, and consultants). This plan was terminated in February 2016. No additional awards may be granted under the 2014 Equity Incentive Plan, however, outstanding awards continue in full effect in accordance with their existing terms.

In 2016, the Company adopted a stock compensation plan (the “2016 Equity Incentive Plan”) pursuant to which the Company may grant stock options, stock purchase rights, restricted stock awards, or stock awards to employees, directors and consultants (including prospective employees, directors, and consultants). No additional awards may be granted under the 2016 Equity Incentive Plan, however, outstanding awards continue in full effect in accordance with their existing terms.

In connection with the IPO on July 2, 2021, the Company's board of directors adopted the 2021 Equity Incentive Plan (the "2021 Equity Incentive Plan"). The 2021 Equity Incentive Plan provides for the grant of incentive stock options ("ISOs"), nonstatutory stock options ("NSOs"), stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based awards and other awards, or collectively, awards. ISOs may be granted only to Xometry employees, including Xometry officers, and the employees of Xometry affiliates. All other awards may be granted to Xometry employees, including our officers, Xometry non-employee directors and consultants and the employees and consultants of Xometry affiliates.

As of March 31, 2022, there were 5,219,760 shares available for the Company to grant under the 2021 Equity Incentive Plan.

Prior to the Company's IPO on July 2, 2021, the fair value of the Company’s common stock was estimated by management as there was no public market for the Company’s common stock. Xometry’s market-based methodology considered a number of objective and subjective factors including third-party valuations of its common stock, the valuation of comparable companies, sales of the Company’s convertible preferred stock to outside investors in arms-length transactions, the Company’s operating and financial performance, the lack of marketability, and general and industry specific economic outlook, amongst others.

The weighted average assumptions for the three months ended March 31, 2022 and 2021 are provided in the following table.


	Three Months Ended March 31,
	2022			2021
Valuation assumptions:
Expected dividend yield	—%			—%
Expected volatility		66	%		52	%
Expected term (years)		6.0			6.0
Risk-free interest rate		1.9	%		1.0	%
Fair value of share	$	34.86		$	5.39

A summary of the status of the Company’s stock option activity and the changes during the three months ended March 31, 2022 are as follows (in millions, except share and per share amounts):


	Number of Shares			Weighted Average Exercise Price Per Share		Average Remaining Contractual Term		Aggregate Intrinsic Value
Exercisable at December 31, 2021		987,622		$	3.35		7.5	$	47.3
Balance at December 31, 2021		3,286,870			6.98		8.4		145.5
Granted		321,649			34.86		—
Exercised		(244,858	)		5.20		—
Forfeited		(86,006	)		7.44		—
Expired		(630	)		3.66		—
Balance at March 31, 2022		3,277,025			9.84		8.3		88.2
Exercisable at March 31, 2022		1,234,215			5.51		7.7		38.6

The weighted average grant date fair value of options granted during the three months ended March 31, 2022 and 2021, was $21.08 and $5.39. The total intrinsic value of options exercised during the three months ended March 31, 2022 and 2021, was $9.7 million and $5.0 million, respectively.

At March 31, 2022 and 2021, there was approximately $25.5 million and $2.7 million, respectively of total unrecognized compensation cost related to unvested stock options. That cost is expected to be recognized over a weighted average period of three years as of March 31, 2022 and one year as of March 31, 2021.

The Company currently uses authorized and unissued shares to satisfy share award exercises.

A summary of the status of the Company’s restricted stock unit activity and the changes during the three months ended March 31, 2022 are as follows (in millions, except share and per share amounts):


	Number of Shares			Weighted Average Grant Date fair value (per share)		Aggregate Intrinsic Value

Unvested RSUs as of December 31, 2021		186,480		$	63.94	$	9.6
Granted		645,431			41.88
Vested		(1,971	)		73.20
Forfeited and cancelled		(14,397	)		59.72
Unvested RSUs as of March 31, 2022		815,543			46.53		30.0

At March 31, 2022, there was approximately $35.3 million of total unrecognized compensation cost related to unvested restricted stock units granted under the 2021 Equity Incentive Plan. That cost is expected to be recognized over a weighted average period of approximately four years as of March 31, 2022. No restricted stock units were granted during the three months ended March 31, 2021.

Total stock-based compensation cost for the three months ended March 31, 2022 and 2021 were as follows (in thousands):


	Three Months Ended March 31,
	2022		2021

Sales and marketing	$	636	$	53
Operations and support		1,423		104
Product development		894		75
General and administrative		503		273
Total stock compensation expense	$	3,456	$	505