Stocks Flow Summary API

Endpoint

GET /v1/flow/stocks/{symbol}/summary

Auth required (X-Api-Key) Rate Limited: Yes Alpha plan+

Parameters

Name	In	Required	Default	Description
`symbol`	path	yes	-	Stock symbol

curl -H "X-Api-Key: YOUR_API_KEY" \
  "https://lab.flashalpha.com/v1/flow/stocks/SPY/summary"

import requests

resp = requests.get(
    "https://lab.flashalpha.com/v1/flow/stocks/SPY/summary",
    headers={"X-Api-Key": "YOUR_API_KEY"}
)
data = resp.json()
print(f"Net share volume: {data['netVolume']:,}")

const resp = await fetch(
  "https://lab.flashalpha.com/v1/flow/stocks/SPY/summary",
  { headers: { "X-Api-Key": "YOUR_API_KEY" } }
);
const data = await resp.json();
console.log("Net share volume: " + data.netVolume.toLocaleString());

API Key

Response

{
  "symbol": "SPY",
  "totalTrades": 184320,
  "buyVolume": 28452100,
  "sellVolume": 26318450,
  "midVolume": 1284200,
  "netVolume": 2133650,
  "biggestSingleTrade": 250000,
  "lastTradeUtc": "2026-05-12T18:42:09.812Z"
}

Key Response Fields

Field	Type	Description
`symbol`	string	Uppercase stock symbol
`totalTrades`	integer	Total buffered stock trades
`buyVolume`	integer	Buy-classified share volume
`sellVolume`	integer	Sell-classified share volume
`midVolume`	integer	Mid/unknown-side share volume
`netVolume`	integer	`buyVolume - sellVolume`
`biggestSingleTrade`	integer	Largest single stock trade size
`lastTradeUtc`	string/null	Latest trade timestamp; omitted when no stock trade buffer exists

Errors

Status	Description
`403`	Requires Alpha plan or higher
`502`	Upstream flow data source unavailable

About

Aggregated stock-flow totals across the in-memory buffer for a symbol. Volumes are in shares. netVolume is the headline directional pressure indicator for the equity tape.

Common Use Cases

Headline buy/sell pressure - surface buyVolume vs sellVolume and the signed netVolume as the directional-pressure tile on an equity-tape dashboard
Rank a watchlist - sort tickers by absolute netVolume to push the most one-sided names to the top of a scanner
Spot block-driven tape - compare biggestSingleTrade to typical lot size to flag when a single institutional print is moving the totals
Measure conviction vs noise - weigh netVolume against midVolume to discount sessions where most flow crossed at the mid with no clear aggressor
Gate on tape freshness - check lastTradeUtc (and its null case) to confirm the name is actively trading before acting on the totals
Normalize across names - divide netVolume by totalTrades for a per-trade imbalance that compares thin and heavy tapes on the same scale

Complementary endpoints

Stocks Recent - drill from the totals into the underlying per-trade tape
Stocks Leaderboard - the same net-notional ranking across the whole equity universe
Stocks Cumulative - watch how netVolume accumulates minute-by-minute
Options Summary - the matching aggregated flow totals for the options tape