Options and Flow Concepts
Trade execution side, buy vs sell inference, sentiment derivation, options dictionary, aggregation mode, and unusual options activity (UOA).
This article covers the foundational concepts you need to read the TradingFlow data feed: how we infer trade direction, derive sentiment, and identify unusual activity.
Trade Execution Side (side)
The side field shows where the trade executed relative to the bid-ask spread:
| Side | Description | Interpretation |
|---|---|---|
| AASK | Above Ask | Very aggressive buyer — strong conviction |
| ASK | At Ask | Aggressive buyer — willing to pay the offer |
| MID | Between Bid/Ask | Neutral — could be either party |
| BID | At Bid | Aggressive seller — hitting the bid |
| BBID | Below Bid | Very aggressive seller — desperate to exit |
- BID = highest price buyers are willing to pay
- ASK = lowest price sellers will accept
- A buyer paying at ASK is "crossing the spread" to get filled now (urgency). A seller at BID is "hitting the bid" to exit now.
Buy vs Sell: Who Is the Aggressor?
We don't have a literal "buy" or "sell" flag. We infer the aggressor from where the trade printed:
- ASK or above → likely buyer (aggressor)
- BID or below → likely seller (aggressor)
- MID → unknown (could be spread or market maker)
Sentiment Derivation (sentiment)
Sentiment is derived from option type (call/put) and side:
| Option | Side (aggressor) | Sentiment |
|---|---|---|
| CALL | Buyer (ASK) | BULLISH |
| CALL | Seller (BID) | BEARISH |
| PUT | Buyer (ASK) | BEARISH |
| PUT | Seller (BID) | BULLISH |
| Any | MID | NEUTRAL |
So: buyer paying up for calls = bullish; buyer paying up for puts = bearish.
Options Dictionary (Core Fields)
| Term | Field | Definition |
|---|---|---|
| Put/Call | put_call | CALL (right to buy) or PUT (right to sell) |
| Strike | strike | Price at which the option can be exercised |
| Expiration | expiration_date | Contract expiry date |
| Size | size | Number of contracts traded |
| Premium | premium | Total dollar value: price × size × 100 |
| Moneyness | moneyness | ITM, ATM, or OTM vs current stock price |
Aggregation Mode
TradingFlow can show aggregated or raw trades:
- Aggregated (default): Trades in the same option in the same second are combined into one row. Use this to spot block trades that were split into many small prints.
- Raw: Every trade as reported. Use when you need exact Time & Sales detail.
When aggregated, size and premium are summed; trade_count shows how many raw trades were combined.
Unusual Options Activity (UOA)
UOA means options volume for a stock is much higher than its average daily options volume.
- Relative Volume = Today's options volume ÷ Average daily options volume
- ≥ 2.0 = double normal — worth watching
- ≥ 3.0 = highly unusual
- ≥ 5.0 = extremely unusual — major catalyst possible
Volume vs number of trades: A few very large trades (block trades) often point to institutional flow. Many small trades are often retail or market makers. Focus on block-sized flow for directional conviction.
For deeper metrics (DEX, DEI, GEX) and option chain concepts, see Greeks and GEX and Option Chain and OI.