Nydar's Dark Pool Volume widget tracks institutional off-exchange activity from FINRA ATS data — ranking up to 30 stocks by weekly volume, flagging surge (1.5x+) and drop (0.5x or below) deviations against a 4-week trailing average
Nydar's Dark Pool Volume widget is an institutional activity tracker that surfaces weekly off-exchange trading data from FINRA's Alternative Trading System (ATS) Transparency dataset, ranking up to 30 US stocks by dark pool share volume and flagging unusual activity where volume deviates 1.5x above or 0.5x below the stock's 4-week trailing average. Dark pools handle approximately 40-45% of all US equity volume according to FINRA reporting, making this data essential for understanding where institutional capital is moving. Nydar queries the FINRA ATS API directly with a 24-hour cache cycle, processing up to 5,000 entries per request to calculate volume change ratios, trade counts, and directional deviation tags (Surge or Drop) for each stock.
Nydar filters exclusively for Tier 1 NMS stocks — the highest-liquidity US equities — and compares the most recent reporting week against a trailing average calculated from up to 4 prior weeks of data. This approach follows the methodology described by Haim Mendelson and Carole Comerton-Forde in their research on dark pool transparency published in the Journal of Financial Economics (2015), which demonstrated that ATS volume data carries predictive value for future volatility and institutional positioning changes. Nydar's widget presents this data in 2 views: Top Volume (ranked by absolute weekly share volume) and Unusual (ranked by deviation magnitude from the trailing average).
Nydar's Top Volume view ranks stocks by total weekly dark pool share volume. Nydar queries the most recent 2 weeks of FINRA data (up to 500 entries), identifies the latest complete reporting week, and sorts by totalWeeklyShareQuantity descending. The top 30 results display each stock's ticker symbol, weekly share volume, total trade count, and reporting week start date.
Nydar's Unusual view detects deviations from normal dark pool activity. Nydar queries 6 weeks of FINRA data (up to 5,000 entries), calculates each stock's average weekly volume over the 4 trailing weeks, and flags stocks where the most recent week's ratio exceeds 1.5x (Surge) or drops below 0.5x (Drop). Results are sorted by deviation magnitude.
Nydar queries the FINRA ATS Transparency API at api.finra.org/data/group/otcMarket/name/weeklySummary using POST requests with date range and domain filters. No authentication is required — FINRA provides this data as a public transparency feed. Nydar filters for tierIdentifier: T1 (Tier 1 NMS stocks) to focus on the highest-liquidity names.
Nydar's unusual activity algorithm queries 6 weeks of FINRA data (up to 5,000 rows), groups entries by symbol, calculates the average weekly volume over the 4 trailing weeks (excluding the most recent week), then computes the ratio: volumeChangeRatio = currentWeekVolume / avgPriorWeeklyVolume. Stocks with a ratio at or above 1.5 are tagged Surge; stocks at or below 0.5 are tagged Drop. Results are sorted by abs(ratio - 1.0) descending so the most extreme deviations appear first.
Nydar caches dark pool data with a 24-hour TTL (86,400 seconds). Since FINRA publishes ATS data once per week with approximately 2 weeks of reporting delay, a daily cache cycle ensures fresh data is picked up within 24 hours of each FINRA publication while avoiding unnecessary API calls. Nydar's per-ticker history endpoint supports up to 52 weeks (1 year) of lookback data.
Nydar's Top Volume view queries up to 500 entries per FINRA request and returns the top 20-100 stocks (configurable via API parameter, default 20). The Unusual view queries up to 5,000 entries to ensure sufficient coverage across all actively traded symbols. Per-ticker history returns up to 104 data points (52 weeks x 2 query overlap) for individual stock dark pool timelines.
A Surge tag in Nydar's Dark Pool widget means the stock's dark pool volume exceeded 1.5x its 4-week trailing average. A ratio of 3.0x means dark pool volume is triple the typical weekly level. Surges can indicate institutional accumulation, block trades ahead of catalysts, or hedging activity. Albert Kyle's lambda model of market microstructure, published in Econometrica (1985), demonstrates that informed traders prefer venues with minimal price impact — exactly what dark pools provide.
A Drop tag in Nydar's widget means dark pool activity has fallen to 0.5x or below the stock's 4-week average. This can signal that institutions have finished building a position, are moving activity to lit exchanges for deliberate price impact, or are reducing exposure. A sudden drop after weeks of elevated dark pool activity is particularly noteworthy — it suggests the accumulation phase is complete.
Nydar computes the volume change ratio as current weekly volume divided by the average of up to 4 prior weeks. Ratios above 1.5x are highlighted in amber as noteworthy surges. Ratios below 0.5x are highlighted in cyan, indicating notably reduced activity. Values near 1.0x represent normal trading patterns. Nydar rounds ratios to 2 decimal places and displays them with an "x avg" suffix for clarity.
Nydar displays the weekly trade count alongside volume for each stock. High volume with a low trade count suggests institutional block orders — large single transactions executed off-exchange to avoid market impact. High volume with a high trade count suggests algorithmic execution, where a large parent order is broken into many smaller child orders. This distinction follows the VWAP execution framework described by Robert Kissell in The Science of Algorithmic Trading (Academic Press, 2013).
| Widget | Data Source | Shows | Best For |
|---|---|---|---|
| Dark Pool Volume | FINRA ATS (weekly, ~2wk delay) | Off-exchange volume, trade count, surge/drop deviation | Institutional accumulation/distribution patterns |
| Options Flow | Real-time options exchanges | Unusual options volume, Vol/OI ratio, Greeks, sweeps | Directional bets, hedging activity, catalyst plays |
| Short Interest | Exchange-reported (bi-monthly) | Short % of float, days to cover, utilization | Short squeeze setups, crowded trades |
| FTD (Failure to Deliver) | SEC (bi-monthly, ~3wk delay) | Settlement failures by symbol, dollar value, share count | Naked shorting signals, forced buy-in events |
| Institutional Holdings | SEC 13F filings (quarterly) | Fund positions from 500+ institutions | Long-term positioning, fund overlap analysis |
| Congressional Trades | STOCK Act disclosures | Congress member trades, timing, amounts | Political insider activity, regulatory signals |
| Retail Flow | Reddit, social sentiment | Retail attention, mention velocity, sentiment | Meme stock momentum, crowding risk |
All 7 widgets are available in Nydar's WSB Trading Floor, which combines 16 alternative data sources into a single dashboard view.
Check the Unusual view for signals
Start with Nydar's Unusual view to spot stocks with volume surges. A ratio above 2.0x deserves further investigation — open the stock in Nydar's charting widget and look for recent price action that might explain the institutional interest.
Compare dark pool activity to price action
Rising dark pool volume on a stock with a flat or declining price can signal quiet accumulation. Institutions buy in dark pools specifically to avoid moving the price — so the price move often comes later. Nydar's charting widget with its 105 technical indicators helps identify whether price has begun responding to the dark pool activity.
Cross-reference with Nydar's Options Flow widget
When Nydar flags a dark pool surge on a ticker, check the Options Flow widget for unusual call or put activity. Institutional moves often show up in both dark pools and options markets simultaneously. A dark pool surge combined with unusual call volume is a stronger accumulation signal than either alone.
Check Nydar's Short Interest and FTD widgets
A dark pool surge on a heavily shorted stock (visible in Nydar's Short Interest widget) can indicate short covering or new long positioning against the short thesis. Cross-reference with FTD data for potential forced buy-in catalysts.
Track volume trends over multiple weeks
A single week of elevated dark pool volume could be noise. Two or three consecutive weeks of above-average activity is a stronger signal that institutions are building or unwinding a position systematically. Nydar's per-ticker history endpoint supports up to 52 weeks of lookback for individual stocks.
Nydar shows data with approximately 2 weeks of delay. FINRA publishes ATS data with a regulatory lag to protect institutional participant identity. Nydar's widget shows institutional activity that happened in the past, not what is happening today. The value is in spotting persistent accumulation or distribution patterns that unfold over weeks.
Dark pool volume does not reveal trade direction. High dark pool volume in Nydar's widget could represent buying or selling. The FINRA ATS data shows that large orders were executed off-exchange, but not whether institutions were accumulating or distributing. Combine Nydar's dark pool signals with the Options Flow and Short Interest widgets for directional clues.
Large-cap stocks dominate the Top Volume view. Blue-chip names like major tech and financial stocks consistently rank highest in Nydar's Top Volume view simply because they trade the most shares overall. The Unusual view is more useful for finding actionable deviations from a stock's normal dark pool activity level.
Nydar filters for Tier 1 NMS stocks only. The widget shows dark pool data exclusively for Tier 1 (NMS) securities — the most liquid US equities. Lower-tier stocks, OTC securities, and non-US equities are not included in FINRA's ATS Transparency feed and therefore do not appear in Nydar's dark pool data.
FINRA OTC Transparency
Official ATS weekly summary data reported by all registered dark pools operating in the US equity market. Nydar queries the weeklySummary endpoint directly — no third-party intermediary.
Alternative Trading Systems
Covers all major dark pool venues including institutional crossing networks and broker-dealer internalization. Dark pools handle approximately 40-45% of all US equity trading volume.
Nydar caches FINRA data with a 24-hour TTL. FINRA publishes new data weekly with approximately 2 weeks of reporting delay.
Options Flow Widget
Track unusual options activity alongside Nydar's dark pool data
Short Interest Widget
Short % of float, days to cover, and squeeze setups
FTD Widget
SEC failure-to-deliver data and settlement failure patterns
Retail Flow Widget
Reddit sentiment and retail attention data for contrast with dark pool signals
Market Microstructure Guide
How orders flow through dark pools and lit exchanges
WSB Trading Floor
16 alternative data widgets including dark pool, short interest, FTD, and congressional trades
Last reviewed: March 2026