Monthly Expiry

Monthly expiry contracts accumulate open interest (and, on active sessions, volume) across the whole month rather than the single week a weekly contract lives for, which is why monthly levels are read as the more durable support/resistance signal — the walls DeltaK's COA engine weighs most heavily aren't the ones that reset every Tuesday or Thursday.

It's also the contract most closely tied to futures rollover — the bulk of a month's directional futures positioning typically concentrates in the current series right up until the days before its own expiry, then shifts over to the next month as traders roll their exposure forward.

Example: a NIFTY monthly contract's open interest at 24,800 that's been building for four straight weekly cycles is a far more durable signal of committed capital than the same strike's OI on a weekly contract that's only two sessions old — the monthly number has survived more sessions of testing.