N-MFP3 0001107414 XXXXXXXX 2026-09-30 STATE STREET INSTITUTIONAL INVESTMENT TRUST 0001107414 549300P1E098W6ES7M39 State Street Treasury Obligations Money Market Fund 549300Q6TZ3O71NFFG47 S000058519 1 N N 333-30810 SSGA Funds Management, Inc. 801-60103 Ernst & Young LLP Boston MA SSGA Funds Management, Inc. SS&C GIDS, Inc. 0000027048 084-00448 Y 0001094885 Treasury Plus Money Market Portfolio S000019934 N N Government N N 1 1 74647857875.94 74647857875.94 0.9920 0.9920 2026-09-01 75011344549.54 75261344549.54 0.9887 0.9920 2026-09-02 68651334400.38 68901334400.38 0.9877 0.9913 2026-09-03 67446276763.89 67696276763.89 0.9873 0.9909 2026-09-04 67010148809.22 67290148809.22 0.9909 0.9950 2026-09-08 66880633502.61 67130633502.61 0.9872 0.9909 2026-09-09 69168411382.72 69418411382.72 0.9876 0.9911 2026-09-10 66804847839.53 67054847839.53 0.9869 0.9906 2026-09-11 66241085941.38 66491085941.38 0.9869 0.9906 2026-09-14 68547141911.44 68547141911.44 0.9909 0.9909 2026-09-15 69549445750.45 69549445750.45 0.9910 0.9910 2026-09-16 69029760147.85 69029760147.85 0.9909 0.9909 2026-09-17 68990353604.34 68990353604.34 0.9907 0.9907 2026-09-18 68504383011.01 68504383011.01 0.9907 0.9907 2026-09-21 68644394178.35 68644394178.35 0.9907 0.9907 2026-09-22 69332651735.32 69332651735.32 0.9908 0.9908 2026-09-23 68086733159.30 68086733159.30 0.9905 0.9905 2026-09-24 68261890993.80 68261890993.80 0.9904 0.9904 2026-09-25 66879106088.50 66879106088.50 0.9903 0.9903 2026-09-28 63924928323.77 63924928323.77 0.9898 0.9898 2026-09-29 68242899927.00 68242899927.00 0.9910 0.9910 2026-09-30 0.00 3125961166.58 3125961166.58 0.00 10697992.68 3115263173.90 3115345275.7900 Y 1.0000 0.0373 2026-09-01 0.0373 2026-09-02 0.0374 2026-09-03 0.0374 2026-09-04 0.0374 2026-09-08 0.0374 2026-09-09 0.0374 2026-09-10 0.0374 2026-09-11 0.0374 2026-09-14 0.0374 2026-09-15 0.0374 2026-09-16 0.0376 2026-09-17 0.0382 2026-09-18 0.0384 2026-09-21 0.0386 2026-09-22 0.0388 2026-09-23 0.0388 2026-09-24 0.0389 2026-09-25 0.0390 2026-09-28 0.0390 2026-09-29 0.0391 2026-09-30 0.9999 2026-09-01 0.9999 2026-09-02 0.9999 2026-09-03 0.9999 2026-09-04 0.9999 2026-09-08 0.9999 2026-09-09 0.9999 2026-09-10 0.9998 2026-09-11 0.9998 2026-09-14 0.9998 2026-09-15 0.9998 2026-09-16 0.9998 2026-09-17 0.9998 2026-09-18 0.9998 2026-09-21 0.9998 2026-09-22 0.9998 2026-09-23 0.9998 2026-09-24 0.9998 2026-09-25 0.9998 2026-09-28 0.9998 2026-09-29 0.9998 2026-09-30 N N A C000192374 1000000000.00 3115263173.90 3115345275.7900 0.9999 2026-09-01 0.9999 2026-09-02 0.9999 2026-09-03 0.9999 2026-09-04 0.9999 2026-09-08 0.9999 2026-09-09 0.9999 2026-09-10 0.9998 2026-09-11 0.9998 2026-09-14 0.9998 2026-09-15 0.9998 2026-09-16 0.9998 2026-09-17 0.9998 2026-09-18 0.9998 2026-09-21 0.9998 2026-09-22 0.9998 2026-09-23 0.9998 2026-09-24 0.9998 2026-09-25 0.9998 2026-09-28 0.9998 2026-09-29 0.9998 2026-09-30 11605081.97 11602414.78 2026-09-01 11602414.78 0.00 2026-09-02 11.48 9.70 2026-09-03 0.00 2217.80 2026-09-04 0.00 0.00 2026-09-08 0.00 0.00 2026-09-09 0.00 0.00 2026-09-10 0.00 0.00 2026-09-11 0.00 0.00 2026-09-14 0.00 0.00 2026-09-15 0.00 0.00 2026-09-16 0.00 0.00 2026-09-17 0.00 0.00 2026-09-18 0.00 750000000.00 2026-09-21 0.00 0.00 2026-09-22 0.00 0.00 2026-09-23 0.00 0.00 2026-09-24 769200000.00 95400352.77 2026-09-25 0.00 0.00 2026-09-28 0.00 257672690.00 2026-09-29 0.00 145558376.00 2026-09-30 792407508.23 1260236061.05 0.0365 2026-09-01 0.0365 2026-09-02 0.0366 2026-09-03 0.0366 2026-09-04 0.0366 2026-09-08 0.0366 2026-09-09 0.0366 2026-09-10 0.0366 2026-09-11 0.0366 2026-09-14 0.0366 2026-09-15 0.0366 2026-09-16 0.0368 2026-09-17 0.0374 2026-09-18 0.0376 2026-09-21 0.0378 2026-09-22 0.0380 2026-09-23 0.0380 2026-09-24 0.0381 2026-09-25 0.0382 2026-09-28 0.0382 2026-09-29 0.0383 2026-09-30 Y 86232.00 Non-financial corporation 0.9999 0.00 N State Street Treasury Plus Money Market Portfolio State Street Treasury Plus Money Market Portfolio FSSgAK183 5493008OWE0VKOXO4934 FSSgAK183 Investment Company Y 2026-10-01 2026-10-01 2026-10-01 N N N 0.0000 3125961166.58 3125961166.58 1.0000 N Y Y N STATE STREET INSTITUTIONAL INVESTMENT TRUST 2026-10-07 /s/ Chad Hallett Chad Hallett Deputy Treasurer