Solana Up/Down order book microstructure on Polymarket

• 687 SOL Up/Down markets, led by 470 five-minute contracts
• Average market spread of 0.0262 (median 0.0200) - mid-pack among the eight assets
• Average top-of-book liquidity of about $18,132 per market over three days
• 2.63% of the last 24 hours of SOL book snapshots were crossed
• All 687 markets settle on chainlink_twap reference prices

The archive carries 687 Solana Up/Down markets as of 2026-10-17: 470 at 5 minutes, 204 at 15 minutes and 13 at 4 hours. The 4-hour count is small for every asset in the basket, so the meaningful sample is the 5- and 15-minute pair, which together account for 674 markets.

297 SOL markets have resolved, split 146 up to 151 down (49.2% up) - the closest to a true coin flip in the basket. That near-even split is a useful sanity check that the grading direction is not systematically biased toward one side for this asset.

Solana's average spread is 0.0262 with a median of 0.0200 - about two ticks wide at the median. That places it behind BTC (0.0115), ETH (0.0139), XRP (0.0259) and just ahead of Dogecoin (0.0363) - a genuinely mid-pack book.

Depth follows the same ranking. Trailing three-day top-of-book liquidity averages about $18,132 per SOL market, above XRP's $16,649 and well above BNB, HYPE and ZEC, but less than half of ETH's. A 5-minute SOL contract can absorb typical order sizes without much slippage, though less than BTC or ETH.

import requests

BASE = "https://api.polyorderbooks.com/v1"
HEADERS = {"X-API-Key": "your-key"}

slug = "sol-updown-5m-1787486400"
r = requests.get(
    f"{BASE}/markets/{slug}/metrics",
    headers=HEADERS,
    params={"start_ts": 1787486400, "end_ts": 1787486700, "resolution": "1s"},
)
r.raise_for_status()
pts = r.json()["data"]
liquidity = [p["liquidity"] for p in pts if p["liquidity"] is not None]
print("points:", len(pts), "avg liquidity:", sum(liquidity)/len(liquidity))

Despite the wider spread, Solana reprices nearly as often as Bitcoin: 16,407 of 624,797 snapshots in the last 24 hours were crossed, a rate of 2.63%. That is third-highest behind ETH and BTC and close to both, which tells you the crossed rate tracks volatility and message traffic more than it tracks spread width.

The practical implication is that a SOL backtest needs the same crossed-book filter as BTC and ETH. Skipping it would inject phantom fills at moments the book was internally inconsistent - and on a mid-pack asset those fills can dominate a thin edge.

All 687 Solana markets settle on a Chainlink TWAP reference price. The reference feed captured 67,092 SOL observations by 2026-10-17, spanning spot and twap kinds, so a Solana strategy can be graded against the exact reference series the exchange used.

Because Solana's resolved set is close to a coin flip (49.2% up), it is a good asset for testing strategies that do not rely on directional drift. If an edge only appears on BTC and ETH but vanishes on a near-balanced SOL sample, it is probably an artifact of the up-biased window rather than a general mechanism.

The Starter plan is free, includes order books, prices, and metrics at 250ms resolution, with 3 days of history, 60 requests/min, 1,000/day, 1 free AI backtest, and 3 strategy backtests. No credit card required.

Paid data windows from $19/mo extend history to 30–120 days at higher throughput. Backtest AI add-on is +$19/mo or standalone at $29/mo.

• Polymarket SOL data
• Crypto microstructure data
• Order book API guide