I’m trying to work this out every day but when I calculate the below clients are saying that it does not look right based just wondered if any one could help me work out if what it should be? Contract CTD CUSIP Coupon Conversion Factor Bond clean price Futures price Accrued interest (today) Delivery date used Days to delivery Repo rate Gross Basis (32nds) Net Basis (32nds) Implied Repo TUZ6 91282CNY3 3.375% 0.9569 97.603516 102.066406 1.6736 2026-12-01 80 3.294% -2.0425 -2.0154 3.5795% 3YZ6 91282CLN9 3.5% 0.9374 96.578125 103.066406 1.5918 2026-12-01 80 3.454% -1.1624 -1.1383 3.6170% FVZ6 91282CQD6 3.5% 0.9090 94.962891 104.507813 0.1438 2026-12-01 80 3.630% -1.1108 -1.1077 3.7939% TYZ6 91282CRJ2 4.5% 0.9202 97.851563 106.109375 0.1479 2026-12-31 110 4.377% 6.7109 5.2543 3.8286% UXYZ6 91282CQQ7 4.375% 0.8858 95.542969 107.625000 1.4384 2026-12-31 110 4.250% 6.6798 5.3618 3.6843% USZ6 912810UL0 5.0% 0.8899 95.541016 106.750000 1.6438 2026-12-31 110 4.794% 17.4141 15.4095 3.1726% WNZ6 912810TL2 4.0% 0.7393 80.322266 108.250000 1.3151 2026-12-31 110 4.666% 9.3773 8.5734 3.5919% Repo used: general collateral (GC) repo for TU/3Y/FV/TY/UXY; Bloomberg's FUT_ACTUAL_REPO_RT field for US/WN specifically. Day count is Act/360 throughout. Inputs (as of 2026-09-12): • Futures: TYZ6 (10-Year T-Note, December 2026) • CTD bond: CUSIP 91282CRJ2, 4.5% coupon, maturity 2033-08-31 • Conversion factor (Bloomberg native field): 0.9202 • Bond clean price: 97.8515625 • Futures price: 106.109375 • Repo rate used (live GC repo): 4.3769% • Trade/"as of" date: 2026-09-12 Step 1 — Coupon cycle. Coupons are semi-annual, anchored on the bond's maturity month/day (Aug 31 / Feb 28-29). Last coupon: 2026-08-31. Next coupon: 2027-02-28. So there is no coupon payment date falling between today and delivery. Step 2 — Accrued interest today. AI(today) = (days since last coupon / 182.5) × (coupon/2) = (12 / 182.5) × 2.25 = 0.147945 Step 3 — Delivery date selection. The contract's delivery window runs across the whole December 2026 delivery month (first delivery day 2026-12-01, last delivery day 2026-12-31). The convention we use: test the sign of net carry assuming the position is held to the last delivery day. If carry over that full window is negative, use the first delivery day instead (deliver ASAP to stop bleeding negative carry); if positive, hold to the last delivery day. Carry to 2026-12-31 comes out positive (Step 6 below), so the last delivery day is used. Delivery date: 2026-12-31 Days to delivery: 110 Step 4 — Coupons/accrued interest at delivery. No coupon payment falls in the window (coupons received = 0), so: AI(delivery) = (days from last coupon to delivery / 182.5) × (coupon/2) = (122 / 182.5) × 2.25 = 1.504110 Step 5 — Coupon income. Coupon income = Coupons received + AI(delivery) − AI(today) = 0 + 1.504110 − 0.147945 = 1.356164 Step 6 — Financing cost. Financing cost = (Clean price + AI(today)) × repo × (days/360) = (97.8515625 + 0.147945) × 0.043769 × (110/360) = 98.0 (approx.) × 0.043769 × 0.305556 = 1.310646 Step 7 — Net carry. Net carry = Coupon income − Financing cost = 1.356164 − 1.310646 = 0.045519 (points) → confirms Step 3's assumption (positive, so last delivery day is correct) Step 8 — Gross Basis. Gross Basis = (Clean price − Futures price × Conversion factor) × 32 = (97.8515625 − 106.109375 × 0.9202) × 32 = 6.7109 (32nds) Step 9 — Net Basis. Net Basis = Gross Basis − (Net carry × 32) = 6.7109 − 1.4566 = 5.2543 (32nds) Step 10 — Implied repo (IRR). IRR = [ (Futures price × CF + AI(delivery) + Coupons received) / (Clean price + AI(today)) − 1 ] × (360/days) × 100 = [ (106.109375 × 0.9202 + 1.504110 + 0) / 98.0 (approx.) − 1 ] × (360/110) × 100 = 3.8286%