PMData, if you want lower latency (4.6 ms vs 8.3 ms median), the original WebSocket messages, Chainlink TWAP direct from Chainlink, and a $49/month plan. Telonex, if you need data from before February 2026 or other venues.
Compare
Telonex alternative: PMData vs Telonex
Both record every Polymarket order book update as Parquet. PMData is faster and half the price; Telonex has longer history and more venues.
Last updated
Competitor details as of , per each vendor's public site.
| Feature | PMData | Telonex |
|---|---|---|
| Dataset | Polymarket + Chainlink (no proxy) | Polymarket + Chainlink (proxied), Predict.fun, Binance |
| History | Since 2026-02 | Since 2025-10 |
| Order book | Raw WebSocket messages | Snapshots generated from Telonex's local book |
| Latency (p50 / p99)Receive time minus Polymarket event time | 4.6 / 40.1 ms | 8.3 / 73.1 ms |
| Clock error bound | < 40 µs (AWS PHC) | Not published |
| Collection location | AWS London (Colocated) | Not published |
| Redundancy | 2 WebSocket conn/market, separate networks | 2 WebSocket conn/market |
| Ecosystem | hftbacktest | prediction-market-backtesting |
| Price | $49/mo for full history, personal use license | $99/mo/exchange |
Which should you pick?
Fast markets
PMData
Crypto Up/Down and other short markets, where latency and the Chainlink TWAP decide results. $49/month, 600 free downloads.
Long history and other venues
Telonex
Polymarket data before February 2026, ready-made quote files, or Predict.fun, Binance, and Polymarket Perpetuals.
Latency benchmark
On identical order book events, PMData's collection latency is about 45% lower at both the median and p99.
Collection latency, same 147,052 order book events
Median (p50)
PMData
4.6 ms
Telonex
8.3 ms
0 ms5 ms10 ms
99th percentile (p99)
PMData
40.1 ms
Telonex
73.1 ms
0 ms40 ms80 ms
Methodology
- Sample: nine Polymarket BTC Up/Down 5-minute markets, one per day, each the market starting at 00:00 UTC. Run on August 12, 2026.
- Events: every best bid or best ask change: PMData from its L2 files, Telonex from its quotes channel, excluding boundary seed rows.
- Matching:147,052 events matched one to one (100% of PMData's, 99.997% of Telonex's), so both are measured on identical market events.
- Results: p50 4.585 ms vs 8.260 ms; p99 40.133 ms vs 73.099 ms.
- Clock:PMData's clock error bound is under 40 µs (AWS PHC), so the measured latency is not distorted by clock error.
Switching from Telonex
| Telonex | PMData |
|---|---|
| trades | trades |
| book_snapshot_5 / 25 / full | l2raw messages, rebuild any depth |
| quotes | l2top of the rebuilt book |
| onchain_fills | onchain_fills |
| crypto_prices | streams, streams_twap30s / 60sdirect from Chainlink |
import pandas as pd
url = ("https://api.pmdata.dev/v1/polymarket/l2/2026/07/18/"
"btc-updown-5m-1784332800.parquet")
df = pd.read_parquet(url, storage_options={"api_key": "<YOUR_API_KEY>"})Frequently asked questions
Telonex: 5 free downloads, then $99/month per exchange or $199/month for all. PMData: 600 free downloads plus 50 a month for data older than 3 weeks, then $49/month for all data. See pricing.
No. Telonex starts on 2025-10-11, with on-chain fills from November 2022. PMData starts on 2026-02-01 for crypto Up/Down markets and 2026-05-01 for all markets.
Telonex sells snapshots at 5, 25, or all levels, built from its own local book. PMData stores Polymarket's original book and price_change messages, so you rebuild the book at any depth.
Telonex: prediction-market-backtesting (NautilusTrader). PMData: pm-hftbacktest, which matched live trading in 95.32% of 547 BTC 5-minute markets.
Try PMData on your own backtest
The free tier includes 600 file downloads of tick-level L2, trades, and on-chain fills.