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Contract OI history

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Dec 18, 2026 EXPIRATION

BLK $870.00 Put

BLK261218P00870000

Latest saved OI257Oct 23, 2026
Last change+8vs previous saved observation
Saved market days12Oct 02, 2026 onwards
Daily open interest Hover a point for its date and OI
BLK $870.00 put open interest history 12 saved observations from 2026-10-02 to 2026-10-23. Exact values and changes are listed in the table below. 2571280 2026-10-02: 250 OI2026-10-05: 250 OI2026-10-06: 250 OI2026-10-07: 250 OI2026-10-08: 250 OI2026-10-09: 250 OI2026-10-13: 250 OI2026-10-14: 250 OI2026-10-15: 249 OI2026-10-16: 249 OI2026-10-21: 249 OI2026-10-23: 257 OI Oct 02, 2026Oct 23, 2026

All saved dates are shown. Changes compare consecutive saved observations. Missing observations are not filled with zero.

BLK contract OI by effective market date, newest first
Market dateOpen interestChange vs prior saved day
Oct 23, 2026Viewing257+8
Oct 21, 20262490
Oct 16, 20262490
Oct 15, 2026249-1
Oct 14, 20262500
Oct 13, 20262500
Oct 09, 20262500
Oct 08, 20262500
Oct 07, 20262500
Oct 06, 20262500
Oct 05, 20262500
Oct 02, 2026250No prior observation