Open Interest

Total outstanding derivative contracts — rising OI = new money fueling the move.

Related terms

OptionsContracts giving the RIGHT (not duty) to buy/sell at a price — advanced; their hedging moves spot.
Order BlockThe last opposite candle before an impulsive move — the institution's refined footprint, used as an entry zone.
Overnight / Swap FeeInterest charged (or paid) for holding leveraged positions past the daily rollover.
OvertradingTaking trades outside your plan for action's sake — death by a thousand spreads.
OCO — One Cancels OtherTwo linked orders where one filling cancels the other — powers the bracket.
OHLCOpen, High, Low, Close — the four prices every candle records.

Terms stick when you use them. The Money Circle academy walks you through them step by step.