Options flow and the market tide
Behind every option trade is money: the premium paid for it. Options flow follows that money, how much changed hands in a stock's options, and whether it was paid by buyers in a hurry or taken by sellers. Summed over many stocks it becomes the market tide, one running number for which way the money leans.
Premium, not contracts
Flow counts dollars rather than contracts. A thousand contracts of a $0.05 option are $5,000; a hundred contracts of a $20 option are $200,000. Premium, contracts times price times 100, is what says how much conviction stood behind a trade.
Which side a trade was on
Every trade has a buyer and a seller, so flow asks who was in a hurry: who crossed the spread to get it done. A trade printed at or toward the ask was most likely the buyer paying up; one at or toward the bid, the seller hitting it. A trade at the mid, or with no two-sided quote to compare it with, counts on neither side.
Then the right turns the side into a lean:
- Bullish: calls bought, or puts sold.
- Bearish: calls sold, or puts bought.
Net premium and the tide
For one stock, net premium sums its flow into one number:
net premium = (calls at the ask − calls at the bid) − (puts at the ask − puts at the bid)
Above zero the money leaned bullish, below zero bearish. The market tide is the same sum across many stocks, kept as a running total through the session: a tide that keeps falling all afternoon says the money has been buying puts and selling calls across the market, whatever the index has done.
Large prints
Flow can also be read one trade at a time. A large print, a single contract trading for a lot of premium in a short span, is the options market's equivalent of a block trade. Read it like unusual activity: where it printed against the quote, how far out of the money, how long to expiry, and whether another contract traded the same size at the same moment, the mark of a spread rather than a bet.
The limits
Reading the side from quotes is an inference, not a record. A delayed or wide quote blurs it, a trade at the mid is lost, and one leg of a spread looks like a bet on its own. Hedges look like bets too: puts bought against a stock position read as bearish flow from an investor who is long. Treat the tide as a lean of the money, a context to read the market in, rather than a forecast.
In Options Meerkat
The market strip under the top bar ends with the tide, the session's net premium across every symbol the rounds watch, with its running total over the last two hours (tide -$7.1M ▅▄▃▂▂▁▂▁), green when it leans bullish and red when bearish. Each symbol's net premium is the dashboard's flow column, and the sector heatmap (H, m to the flow) sums it by sector. The news flow (N) puts each ticker's headlines beside its move, net premium, and unusual contracts, and the historical flow (F) lists the large single-contract prints by session, $100,000 and up, filtered by side, right, and symbol. The rounds measure flow between their fetches, so each contract counts on the side of its latest trade in the span: the closer the rounds, the truer the split.