X0201 N-CEN LIVE 0001403166 XXXXXXXX 811-22078 false false false N-1A true Master Trust 811-22078 0001403166 549300EBIIAXTNCMYQ69 C/O UBS ASSET MANAGEMENT (AMERICAS) INC. 12TH FLOOR 1285 AVENUE OF THE AMERICAS NEW YORK 10019 US-NY US 212-821-3000 State Street Bank and Trust Company 1 Lincoln Street Boston 02111 617-786-3000 Custody and Accounting Records. N N N-1A 5 N Heather R. Higgins 000000000 N Meyer Feldberg 000000000 Y Richard R. Burt 000000000 N Alan S. Bernikow 000000000 N Bernard H. Garil 000000000 N Frank Pluchino 001499081 1285 AVENUE OF THE AMERICAS NEW YORK 10019 XXXXXX N N N N N N N UBS Asset Management (US) Inc. 8-21901 000000583 0000000000 Y N Ernst & Young LLP 42 254900H1VLSDPE6LJK37 N N N N N N N Prime CNAV Master Fund S000053209 549300K8VKMIOPMVLW91 N 1 0 0 Money Market Fund N N N N N/A N/A N/A Rule 32a-4 (17 CFR 270.32a-4) Y N N N UBS Asset Management (Americas) Inc. 801-34910 000106838 F88SLSBEMHN5FUSNRO91 N N PricingDirect Inc. 549300WIC0TOJ7N7GD54 N Refinitiv US Holdings Inc. 549300NF240HXJO7N016 N Bloomberg L.P. 549300B56MD0ZC402L06 N ICE Data Services, Inc. 5493000NQ9LYLDBCTL34 N Standard & Poor's Financial Services LLC 549300U4VWNITEKO2881 N IHS Markit Ltd. 549300HLPTRASHS0E726 GB N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Bank - section 17(f)(1) (15 U.S.C. 80a-17(f)(1)) N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N Y UBS Asset Management (Americas) Inc. F88SLSBEMHN5FUSNRO91 Y N N UBS Securities LLC 8-22651 000007654 T6FIZBDPKLYJKFCRVK44 0.00000000 0.00000000 Industrial and Commercial Bank of China Financial Services LLC 8-66471 000131487 5493003O0P1GJ0O8CI80 15656000000.00000000 JPMorgan Chase & Co. 8-35008 000000079 8I5DZWZKVSZI1NUHU748 22735731546.77000000 Mizuho Securities USA LLC 8-37710 000019647 7TK5RJIZDFROZCA6XF66 9907500000.00000000 BNP Paribas Securities Corp. 8-32682 000015794 RCNB6OTYUAMMP879YW96 12681479732.82000000 Deutsche Bank Securities Inc. 8-17822 000002525 9J6MBOOO7BECTDTUZW19 11554463521.13000000 Goldman Sachs & Co. LLC 8-129 000000361 FOR8UP27PHTHYVLBNG30 40319181580.93000000 Barclays Capital Inc. 8-41342 000019714 AC28XWWI3WIBK2824319 81312193308.43000000 Citigroup Global Markets Inc. 8-8177 000007059 MBNUM2BPBDO7JBLYG310 2689310796.05000000 Pershing LLC 8-17574 000007560 ZI8Q1A8EI8LQFJNM0D94 28333490654.60000000 Merrill Lynch, Pierce, Fenner & Smith Incorporated 8-7221 000007691 8NAV47T0Y26Q87Y0QP81 31771194321.86000000 264785094209.28000000 N 3566100180.30000000 Committed 185000000.00000000 N N N Tax-Free Master Fund S000019504 5493006YO58S2QLZBI07 N 1 0 0 Money Market Fund N N N N N/A N/A N/A Rule 32a-4 (17 CFR 270.32a-4) Y N N N UBS Asset Management (Americas) Inc. 801-34910 000106838 F88SLSBEMHN5FUSNRO91 N N Refinitiv US Holdings Inc. 549300NF240HXJO7N016 N PricingDirect Inc. 549300WIC0TOJ7N7GD54 N Standard & Poor's Financial Services LLC 549300U4VWNITEKO2881 N IHS Markit Ltd. 549300HLPTRASHS0E726 GB N Bloomberg L.P. 549300B56MD0ZC402L06 N ICE Data Services, Inc. 5493000NQ9LYLDBCTL34 N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Bank - section 17(f)(1) (15 U.S.C. 80a-17(f)(1)) N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N Y UBS Asset Management (Americas) Inc. F88SLSBEMHN5FUSNRO91 Y N N UBS Securities LLC 8-22651 000007654 T6FIZBDPKLYJKFCRVK44 0.00000000 0.00000000 National Financial Services Corporation 8-26740 000013041 549300EJM5SBRQSYKC50 638100000.00000000 Merrill Lynch, Pierce, Fenner & Smith Incorporated 8-7221 000007691 8NAV47T0Y26Q87Y0QP81 1265811700.00000000 Barclays Capital Inc. 8-41342 000019714 AC28XWWI3WIBK2824319 541760000.00000000 Morgan Stanley & Co. LLC 8-15869 000008209 9R7GPTSO7KV3UQJZQ078 374165000.00000000 JPMorgan Chase & Co. 8-35008 000000079 8I5DZWZKVSZI1NUHU748 1919732300.00000000 Citigroup Global Markets Inc. 8-8177 000007059 MBNUM2BPBDO7JBLYG310 815355000.00000000 U.S. Bancorp 8-35359 000017868 N1GZ7BBF3NP8GI976H15 407610000.00000000 Goldman Sachs & Co. LLC 8-129 000000361 FOR8UP27PHTHYVLBNG30 447893920.45000000 Wells Fargo Securities, LLC 8-65876 000126292 VYVVCKR63DVZZN70PB21 1341435220.15000000 RBC Capital Markets, LLC 8-45411 000031194 549300LCO2FLSSVFFR64 284000000.00000000 8583693140.60000000 N 2644957061.99000000 Committed 185000000.00000000 N N N Treasury Master Fund S000019503 549300XQ6V293JKF0677 N 1 0 0 Money Market Fund N N N N/A N/A N/A Rule 32a-4 (17 CFR 270.32a-4) Y N N N UBS Asset Management (Americas) Inc. 801-34910 000106838 F88SLSBEMHN5FUSNRO91 N N Bloomberg L.P. 549300B56MD0ZC402L06 N Refinitiv US Holdings Inc. 549300NF240HXJO7N016 N PricingDirect Inc. 549300WIC0TOJ7N7GD54 N ICE Data Services, Inc. 5493000NQ9LYLDBCTL34 N IHS Markit Ltd. 549300HLPTRASHS0E726 GB N Standard & Poor's Financial Services LLC 549300U4VWNITEKO2881 N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Bank - section 17(f)(1) (15 U.S.C. 80a-17(f)(1)) N N UBS Asset Management (Americas) Inc. F88SLSBEMHN5FUSNRO91 Y N State Street Bank and Trust Company 571474TGEMMWANRLN572 N Y N UBS Securities LLC 8-22651 000007654 T6FIZBDPKLYJKFCRVK44 0.00000000 0.00000000 Merrill Lynch, Pierce, Fenner & Smith Incorporated 8-7221 000007691 8NAV47T0Y26Q87Y0QP81 25204714084.91000000 Goldman Sachs & Co. LLC 8-129 000000361 FOR8UP27PHTHYVLBNG30 16259000000.00000000 The Bank of New York Mellon 8-35255 000017454 HPFHU0OQ28E4N0NFVK49 195657296897.47000000 JPMorgan Chase & Co. 8-35008 000000079 8I5DZWZKVSZI1NUHU748 5146662084.64000000 BNP Paribas Securities Corp. 8-32682 000015794 RCNB6OTYUAMMP879YW96 244992980173.32000000 Citigroup Global Markets Inc. 8-8177 000007059 MBNUM2BPBDO7JBLYG310 4760507424.65000000 TD Securities (USA) LLC 8-36747 000018476 SUVUFHICNZMP2WKHG940 2559096807.35000000 Mizuho Securities USA LLC 8-37710 000019647 7TK5RJIZDFROZCA6XF66 86159376777.79000000 Barclays Capital Inc. 8-41342 000019714 AC28XWWI3WIBK2824319 255700891536.08000000 MUFG Securities Americas Inc. 8-43026 000019685 K5HU16E3LMSVCCJJJ255 64299671875.00000000 905112130854.70000000 N 17485780640.75000000 Committed 185000000.00000000 N N N Prime Master Fund S000019502 549300EFOVWITFDGF261 N 1 0 0 Money Market Fund N N N N/A N/A N/A Rule 32a-4 (17 CFR 270.32a-4) Y N N N UBS Asset Management (Americas) Inc. 801-34910 000106838 F88SLSBEMHN5FUSNRO91 N N PricingDirect Inc. 549300WIC0TOJ7N7GD54 N Standard & Poor's Financial Services LLC 549300U4VWNITEKO2881 N Bloomberg L.P. 549300B56MD0ZC402L06 N IHS Markit Ltd. 549300HLPTRASHS0E726 GB N Refinitiv US Holdings Inc. 549300NF240HXJO7N016 N ICE Data Services, Inc. 5493000NQ9LYLDBCTL34 N N Deutsche Bank Aktiengesellschaft (London, GB, Branch) 7LTWFZYICNSX8D621K86 GB N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Bank - section 17(f)(1) (15 U.S.C. 80a-17(f)(1)) Euroclear Limited 54930045L3MXWBD27H71 CH N Y Foreign securities depository - rule 17f-7 (17 CFR 270.17f-7) N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N Y UBS Asset Management (Americas) Inc. F88SLSBEMHN5FUSNRO91 Y N N UBS Securities LLC 8-22651 000007654 T6FIZBDPKLYJKFCRVK44 0.00000000 0.00000000 JPMorgan Chase & Co. 8-35008 000000079 8I5DZWZKVSZI1NUHU748 66985593092.52000000 Citigroup Global Markets Inc. 8-8177 000007059 MBNUM2BPBDO7JBLYG310 8821963344.28000000 Pershing LLC 8-17574 000007560 ZI8Q1A8EI8LQFJNM0D94 86732676667.57000000 BNP Paribas Securities Corp. 8-32682 000015794 RCNB6OTYUAMMP879YW96 52281108570.17000000 Industrial and Commercial Bank of China Financial Services LLC 8-66471 000131487 5493003O0P1GJ0O8CI80 40669000000.00000000 Barclays Capital Inc. 8-41342 000019714 AC28XWWI3WIBK2824319 104806081248.25000000 Mizuho Securities USA LLC 8-37710 000019647 7TK5RJIZDFROZCA6XF66 37649000000.00000000 Deutsche Bank Securities Inc. 8-17822 000002525 9J6MBOOO7BECTDTUZW19 39311454836.53000000 Merrill Lynch, Pierce, Fenner & Smith Incorporated 8-7221 000007691 8NAV47T0Y26Q87Y0QP81 72779586799.61000000 ICAP Securities Limited N/A 000019739 213800NMEZS3MD2IUP33 GB 12765308718.79000000 552359898801.60000000 N 12292361952.65000000 Committed 185000000.00000000 N N N Government Master Fund S000054189 54930015XY4J2ENG8G36 N 1 0 0 Money Market Fund N N N N/A N/A N/A Rule 32a-4 (17 CFR 270.32a-4) Y N N N UBS Asset Management (Americas) Inc. 801-34910 000106838 F88SLSBEMHN5FUSNRO91 N N Refinitiv US Holdings Inc. 549300NF240HXJO7N016 N ICE Data Services, Inc. 5493000NQ9LYLDBCTL34 N IHS Markit Ltd. 549300HLPTRASHS0E726 GB N Bloomberg L.P. 549300B56MD0ZC402L06 N Standard & Poor's Financial Services LLC 549300U4VWNITEKO2881 N PricingDirect Inc. 549300WIC0TOJ7N7GD54 N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Bank - section 17(f)(1) (15 U.S.C. 80a-17(f)(1)) N N State Street Bank and Trust Company 571474TGEMMWANRLN572 N Y UBS Asset Management (Americas) Inc. F88SLSBEMHN5FUSNRO91 Y N N UBS Securities LLC 8-22651 000007654 T6FIZBDPKLYJKFCRVK44 0.00000000 0.00000000 MUFG Securities Americas Inc. 8-43026 000019685 K5HU16E3LMSVCCJJJ255 58675000000.00000000 JPMorgan Chase & Co. 8-35008 000000079 8I5DZWZKVSZI1NUHU748 2663466065.09000000 Barclays Capital Inc. 8-41342 000019714 AC28XWWI3WIBK2824319 301188225294.01000000 Citigroup Global Markets Inc. 8-8177 000007059 MBNUM2BPBDO7JBLYG310 2376198173.27000000 BNP Paribas Securities Corp. 8-32682 000015794 RCNB6OTYUAMMP879YW96 22374186308.50000000 Merrill Lynch, Pierce, Fenner & Smith Incorporated 8-7221 000007691 8NAV47T0Y26Q87Y0QP81 9188658599.90000000 Nomura Securities International, Inc. 8-15255 000004297 OXTKY6Q8X53C9ILVV871 3573920416.07000000 TD Securities (USA) LLC 8-36747 000018476 SUVUFHICNZMP2WKHG940 44566599183.86000000 Daiwa Capital Markets America Inc. 8-12242 000001576 M67H5PRC0NQKM73ZAS82 5384046094.84000000 Goldman Sachs & Co. LLC 8-129 000000361 FOR8UP27PHTHYVLBNG30 2907000000.00000000 458896103514.60000000 N 15025314149.15000000 Committed 185000000.00000000 N N N true