What the desk measures
The core measure is premium turnover: for each interval, the contract volume multiplied by the option's last traded price, summed across a liquid window of strikes within about 4% of spot. The window keeps deep out-of-the-money contracts, where large contract counts can carry little money, from distorting the picture.
Turnover is a proxy for where capital changed hands. It does not say whether a trade was a buy, a write, a hedge or a spread leg. That is why the desk pairs it with open-interest change and the price of the underlying before it labels a regime.
| Card | Meaning |
|---|---|
| Net premium flow | Call-led premium turnover minus put-led premium turnover over the session. Positive means call premium dominated. |
| Call turnover and put turnover | Total premium traded on each side, with the most active strike noted. |
| Volume PCR | Put volume divided by call volume. Below 1 means more call volume than put volume. |
| Spot and regime | The underlying level and the current positioning regime label. |
A desk read strip summarises the session in one line, such as the largest single-interval impulse and whether flow was call-led or put-led. Treat it as a headline, then verify it in the charts.
The two charts
Net premium versus spot plots call-led and put-led premium impulses together with the underlying price. Look for impulses that line up with price moves, and for impulses that appear without any price response.
Cumulative net flow builds a running total from the open and shows the call and put share of turnover. A steady slope shows sustained pressure; a total that rises and falls back shows alternating impulses that cancel out. One large bar means little unless it is repeated or followed by price and open-interest confirmation.
Reading the flow tape
Switch between the Flow Tape table and Compact Bars. The table lists each interval with the following columns, and you can search by time, regime or strike, filter to all, call-led or put-led rows, turn on a high-conviction filter and sort by any column.
| Column | What it shows |
|---|---|
| Spot LTP and Price change | The underlying level and its change over the interval. |
| Net premium | Net call-led minus put-led premium turnover for the interval. |
| Call turnover and Put turnover | Premium traded on each side in the interval. |
| Vol PCR | Put volume divided by call volume for the interval. |
| Net OI change | Net change in open interest across the window. |
| Positioning | A regime label such as Long Build, Short Build or Neutral, combining price direction with open-interest expansion or contraction. |
| Signal | A bullish or bearish tilt with a score, summarising the row. |
Regime labels are descriptive. A label such as Short Build combines price direction with rising open interest; it cannot identify the participants or their motive, and near expiry or at-the-money strikes it can flip from one interval to the next.
Controls
- Underlying and expiry. Choose the index and the expiry to analyse. Select a liquid expiry; thin ones give noisy turnover.
- Trading session. Pick the date to view. The header notes when you are looking at a snapshot of a previous session.
- Aggregation. Group the data into 1, 3, 5, 10, 15 or 30-minute intervals. Shorter intervals show timing and noise; longer ones show direction.
- Backtest and live updates. Replay history, or refresh live during market hours.
A confirmation routine
- Read the headline cards, then ask whether the call-led or put-led lean is persistent in the cumulative chart.
- Find the biggest impulse on the flow chart and check what spot did in the same interval.
- On the tape, compare the premium with the net OI change and the regime label for the same rows.
- Check whether the same direction repeats across consecutive intervals; repeated flow matters more than one burst.
- Look at the chain for the strikes involved, including spreads and quotes, before treating any of it as actionable. The option chain guide shows how.
Large flow is activity, not proven intent. The same premium could be directional buying, premium selling, a hedge or one leg of a spread. Use flow to decide where to look next, not what to trade.