N-MFP3 0001060517 XXXXXXXX 2026-06-30 UBS Series Funds 0001060517 54930058UKPXVB81RJ71 UBS Select Treasury Preferred Fund 549300DXQ8KM8WHPPG39 S000018677 1 N N 333-52965 UBS ASSET MANAGEMENT (AMERICAS) LLC 801-34910 Ernst & Young LLP New York NY UBS ASSET MANAGEMENT (AMERICAS) LLC BNY Mellon Investment Servicing (US) Inc. 0000849542 084-01761 Y 0001403166 Treasury Master Fund S000019503 N N Government N Y 1 1 41573447858.26 41573447858.26 0.9996 0.9996 2026-06-01 40535208705.72 40535208705.72 0.9996 0.9996 2026-06-02 41418552132.23 41418552132.23 0.9996 0.9996 2026-06-03 41701974121.68 41701974121.68 0.9996 0.9996 2026-06-04 41570916871.63 41570916871.63 0.9994 0.9994 2026-06-05 41993307699.53 41993307699.53 0.9995 0.9995 2026-06-08 42006719291.62 42006719291.62 0.9995 0.9995 2026-06-09 42451374294.36 42451374294.36 0.9995 0.9995 2026-06-10 41296758378.05 41296758378.05 0.9995 0.9995 2026-06-11 40983978816.01 40983978816.01 0.9994 0.9994 2026-06-12 43268328299.95 43268328299.95 0.9995 0.9995 2026-06-15 43385378813.37 43385378813.37 0.9995 0.9995 2026-06-16 43394013503.05 43394013503.05 0.9994 0.9994 2026-06-17 41564815894.62 41564815894.62 0.9992 0.9992 2026-06-18 42944534758.09 42944534758.09 0.9993 0.9993 2026-06-22 42562186300.46 42562186300.46 0.9993 0.9993 2026-06-23 42754188244.85 42754188244.85 0.9993 0.9993 2026-06-24 41322053284.98 41322053284.98 0.9993 0.9993 2026-06-25 43623597045.07 43623597045.07 0.9992 0.9992 2026-06-26 43429710131.09 43429710131.09 0.9993 0.9993 2026-06-29 41753970792.84 41753970792.84 0.9993 0.9993 2026-06-30 0.00 23726532035.83 0.00 0.00 67527075.06 23659004960.77 23658212708.6400 Y 1.0000 0.0369 2026-06-01 0.0369 2026-06-02 0.0368 2026-06-03 0.0368 2026-06-04 0.0368 2026-06-05 0.0368 2026-06-08 0.0368 2026-06-09 0.0368 2026-06-10 0.0368 2026-06-11 0.0369 2026-06-12 0.0369 2026-06-15 0.0369 2026-06-16 0.0369 2026-06-17 0.0369 2026-06-18 0.0369 2026-06-22 0.0369 2026-06-23 0.0369 2026-06-24 0.0369 2026-06-25 0.0370 2026-06-26 0.0370 2026-06-29 0.0370 2026-06-30 1.0001 2026-06-01 1.0001 2026-06-02 1.0001 2026-06-03 1.0001 2026-06-04 1.0001 2026-06-05 1.0000 2026-06-08 1.0000 2026-06-09 1.0001 2026-06-10 1.0001 2026-06-11 1.0001 2026-06-12 1.0000 2026-06-15 1.0001 2026-06-16 1.0000 2026-06-17 1.0000 2026-06-18 1.0000 2026-06-22 1.0000 2026-06-23 1.0000 2026-06-24 1.0000 2026-06-25 1.0000 2026-06-26 1.0000 2026-06-29 1.0000 2026-06-30 N N Single Class C000051800 50000000.00 23659004960.77 23658212708.6400 1.0001 2026-06-01 1.0001 2026-06-02 1.0001 2026-06-03 1.0001 2026-06-04 1.0001 2026-06-05 1.0000 2026-06-08 1.0000 2026-06-09 1.0001 2026-06-10 1.0001 2026-06-11 1.0001 2026-06-12 1.0000 2026-06-15 1.0001 2026-06-16 1.0000 2026-06-17 1.0000 2026-06-18 1.0000 2026-06-22 1.0000 2026-06-23 1.0000 2026-06-24 1.0000 2026-06-25 1.0000 2026-06-26 1.0000 2026-06-29 1.0000 2026-06-30 974876060.47 408186924.67 2026-06-01 385079789.05 1020859833.51 2026-06-02 395812737.07 386139186.26 2026-06-03 1034005097.10 307991365.23 2026-06-04 325630127.87 443870744.97 2026-06-05 343857440.03 704420974.30 2026-06-08 628710906.22 204649632.34 2026-06-09 254387129.06 214072376.72 2026-06-10 224306710.45 538187856.83 2026-06-11 568394593.57 885090469.98 2026-06-12 1663070890.66 142268749.76 2026-06-15 619276621.50 187354785.03 2026-06-16 811583761.46 1146754274.93 2026-06-17 192257496.56 1226017101.80 2026-06-18 991618266.53 252625610.48 2026-06-22 535906377.14 389385495.68 2026-06-23 416448978.12 764851084.98 2026-06-24 164869535.44 728523186.63 2026-06-25 3020687736.64 711200146.52 2026-06-26 1427018052.21 2258586287.73 2026-06-29 1027001772.80 2279869144.25 2026-06-30 16004800079.95 15200905232.60 0.0355 2026-06-01 0.0355 2026-06-02 0.0355 2026-06-03 0.0354 2026-06-04 0.0354 2026-06-05 0.0354 2026-06-08 0.0354 2026-06-09 0.0354 2026-06-10 0.0354 2026-06-11 0.0355 2026-06-12 0.0355 2026-06-15 0.0355 2026-06-16 0.0355 2026-06-17 0.0355 2026-06-18 0.0355 2026-06-22 0.0355 2026-06-23 0.0355 2026-06-24 0.0356 2026-06-25 0.0356 2026-06-26 0.0356 2026-06-29 0.0357 2026-06-30 Y 782376.00 Non-financial corporation 0.0639 0.00 Broker-dealer 0.0872 0.00 N Treasury Master Fund Treasury Master Fund 81699K911 549300XQ6V293JKF0677 0001403166 81699K911 Investment Company Y 2026-07-01 2026-07-01 2026-07-01 N N N 0.0000 23726532035.83 23726532035.83 1.0000 N Y Y N The master-feeder funds are parties to a written daily liquidity agreement; consistent with SEC staff interpretative guidance, ownership interests in the master fund are categorized as a Daily Liquid Asset/Weekly Liquid Asset by the feeder funds. UBS Series Funds 2026-07-08 /s/Rose Ann Bubloski Rose Ann Bubloski Vice President