MispriaANALYTICS
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Why Up or Down prices jump in the final minute

Watch a Polymarket crypto Up or Down market near its close and the price often runs to 1¢ or 99¢. Our records of every window since Aug 7, 2026 show how much of that run is already done one minute before the close, why the 60-second average locks it in, and how often it still goes the other way.
GuideData as of Oct 21, 2026nights Aug 7 – Oct 21, 2026published Oct 22, 2026
64.7%
of 5-minute windows priced 95¢+ one minute before the close
16.7% halfway through · 87,498 windows

Two snapshots per window

For every window we keep the order book's price at two moments: halfway through the window, and one minute before the close (T−60 s). Comparing the two shows how much of the final jump is already priced in before the last minute starts.

Most of the move happens before the final minute

Share of windows priced at 95¢ or more on either side
0%20%40%60%80%100%5-minute · halfway through: 17%17%5-minute · one minute before the close: 65%65%5-minute15-minute · halfway through: 11%11%15-minute · one minute before the close: 79%79%15-minutehourly · halfway through: 8%8%hourly · one minute before the close: 82%82%hourly
halfway throughone minute before the close
Order book, Aug 7 – Oct 21, 2026
durationwindows95¢+ halfway95¢+ at T−60 s99¢+ at T−60 sBrier halfwayBrier at T−60 s
5-minute87,49816.7%64.7%32.1%0.14310.0599
15-minute29,15710.5%79.3%59.1%0.15120.0345
hourly7,2918.1%81.8%66.6%0.16610.0279
95¢+ = the Up price at 95¢ or more, or at 5¢ or less. Brier score: lower is sharper; 0.25 is a coin flip.

Halfway through, 16.7% of 5-minute windows were already priced at 95¢ or more on one side; one minute before the close, 64.7% were. At 15 minutes the share went from 10.5% to 79.3%, and on hourly windows from 8.1% to 81.8%.

The market's Brier score fell 2.4-fold between the two snapshots on 5-minute windows (0.1431 to 0.0599), 4.4-fold on 15-minute windows and 6.0-fold on hourly ones. The longer the window, the more of it has already happened by the last minute.

The favourite changes more often than it looks

The side that was favourite halfway through was no longer the favourite one minute before the close in 18.6% of 5-minute windows, 21.0% of 15-minute windows and 24.3% of hourly ones. When it switched, the new favourite won 83.7%, 90.9% and 93.0% of the time.

These rates held across the period: 18.9% then 18.4% on 5-minute windows (Aug 7 – Sep 13, then Sep 14 – Oct 21), 24.1% then 24.4% on hourly ones.

Why 5- and 15-minute markets lock in

These markets settle on the average of the last 60 one-second prices, not on the last price. One minute before the close none of that average is fixed yet; each second then fixes one sixtieth of it. An average of a random path over a minute moves less than the path's end point: its standard deviation is about √(1/3), or 58%, of the end point's.

With Bitcoin's median realized volatility over the period (26.2% a year), one standard deviation of the spot price over a minute is about 3.6 bps; for the 60-second average it is about 2.1 bps. Against a median Bitcoin 5-minute close of 4.35 bps from the price to beat, a window that is a few basis points away from its line one minute out has little room left to cross it.

What is still open before the close (Bitcoin, 1 standard deviation)
0246120 s90 s60 s30 s0 sbpsseconds before the close →median Bitcoin 5-minute close: 4.35 bpssettled on the 60-second average (5- and 15-minute rule) · 120 s before the close: 4.2 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 118 s before the close: 4.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 116 s before the close: 4.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 114 s before the close: 4.0 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 112 s before the close: 4.0 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 110 s before the close: 3.9 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 108 s before the close: 3.8 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 106 s before the close: 3.8 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 104 s before the close: 3.7 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 102 s before the close: 3.7 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 100 s before the close: 3.6 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 98 s before the close: 3.5 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 96 s before the close: 3.5 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 94 s before the close: 3.4 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 92 s before the close: 3.4 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 90 s before the close: 3.3 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 88 s before the close: 3.2 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 86 s before the close: 3.2 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 84 s before the close: 3.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 82 s before the close: 3.0 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 80 s before the close: 2.9 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 78 s before the close: 2.9 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 76 s before the close: 2.8 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 74 s before the close: 2.7 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 72 s before the close: 2.6 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 70 s before the close: 2.6 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 68 s before the close: 2.5 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 66 s before the close: 2.4 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 64 s before the close: 2.3 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 62 s before the close: 2.2 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 60 s before the close: 2.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 58 s before the close: 2.0 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 56 s before the close: 1.9 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 54 s before the close: 1.8 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 52 s before the close: 1.7 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 50 s before the close: 1.6 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 48 s before the close: 1.5 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 46 s before the close: 1.4 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 44 s before the close: 1.3 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 42 s before the close: 1.2 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 40 s before the close: 1.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 38 s before the close: 1.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 36 s before the close: 1.0 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 34 s before the close: 0.9 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 32 s before the close: 0.8 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 30 s before the close: 0.7 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 28 s before the close: 0.7 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 26 s before the close: 0.6 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 24 s before the close: 0.5 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 22 s before the close: 0.5 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 20 s before the close: 0.4 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 18 s before the close: 0.3 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 16 s before the close: 0.3 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 14 s before the close: 0.2 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 12 s before the close: 0.2 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 10 s before the close: 0.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 8 s before the close: 0.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 6 s before the close: 0.1 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 4 s before the close: 0.0 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 2 s before the close: 0.0 bps on the averagesettled on the 60-second average (5- and 15-minute rule) · 0 s before the close: 0.0 bps on the averageif it settled on the last price · 120 s before the close: 5.1 bps on the last priceif it settled on the last price · 118 s before the close: 5.1 bps on the last priceif it settled on the last price · 116 s before the close: 5.0 bps on the last priceif it settled on the last price · 114 s before the close: 5.0 bps on the last priceif it settled on the last price · 112 s before the close: 4.9 bps on the last priceif it settled on the last price · 110 s before the close: 4.9 bps on the last priceif it settled on the last price · 108 s before the close: 4.8 bps on the last priceif it settled on the last price · 106 s before the close: 4.8 bps on the last priceif it settled on the last price · 104 s before the close: 4.8 bps on the last priceif it settled on the last price · 102 s before the close: 4.7 bps on the last priceif it settled on the last price · 100 s before the close: 4.7 bps on the last priceif it settled on the last price · 98 s before the close: 4.6 bps on the last priceif it settled on the last price · 96 s before the close: 4.6 bps on the last priceif it settled on the last price · 94 s before the close: 4.5 bps on the last priceif it settled on the last price · 92 s before the close: 4.5 bps on the last priceif it settled on the last price · 90 s before the close: 4.4 bps on the last priceif it settled on the last price · 88 s before the close: 4.4 bps on the last priceif it settled on the last price · 86 s before the close: 4.3 bps on the last priceif it settled on the last price · 84 s before the close: 4.3 bps on the last priceif it settled on the last price · 82 s before the close: 4.2 bps on the last priceif it settled on the last price · 80 s before the close: 4.2 bps on the last priceif it settled on the last price · 78 s before the close: 4.1 bps on the last priceif it settled on the last price · 76 s before the close: 4.1 bps on the last priceif it settled on the last price · 74 s before the close: 4.0 bps on the last priceif it settled on the last price · 72 s before the close: 4.0 bps on the last priceif it settled on the last price · 70 s before the close: 3.9 bps on the last priceif it settled on the last price · 68 s before the close: 3.8 bps on the last priceif it settled on the last price · 66 s before the close: 3.8 bps on the last priceif it settled on the last price · 64 s before the close: 3.7 bps on the last priceif it settled on the last price · 62 s before the close: 3.7 bps on the last priceif it settled on the last price · 60 s before the close: 3.6 bps on the last priceif it settled on the last price · 58 s before the close: 3.5 bps on the last priceif it settled on the last price · 56 s before the close: 3.5 bps on the last priceif it settled on the last price · 54 s before the close: 3.4 bps on the last priceif it settled on the last price · 52 s before the close: 3.4 bps on the last priceif it settled on the last price · 50 s before the close: 3.3 bps on the last priceif it settled on the last price · 48 s before the close: 3.2 bps on the last priceif it settled on the last price · 46 s before the close: 3.2 bps on the last priceif it settled on the last price · 44 s before the close: 3.1 bps on the last priceif it settled on the last price · 42 s before the close: 3.0 bps on the last priceif it settled on the last price · 40 s before the close: 2.9 bps on the last priceif it settled on the last price · 38 s before the close: 2.9 bps on the last priceif it settled on the last price · 36 s before the close: 2.8 bps on the last priceif it settled on the last price · 34 s before the close: 2.7 bps on the last priceif it settled on the last price · 32 s before the close: 2.6 bps on the last priceif it settled on the last price · 30 s before the close: 2.6 bps on the last priceif it settled on the last price · 28 s before the close: 2.5 bps on the last priceif it settled on the last price · 26 s before the close: 2.4 bps on the last priceif it settled on the last price · 24 s before the close: 2.3 bps on the last priceif it settled on the last price · 22 s before the close: 2.2 bps on the last priceif it settled on the last price · 20 s before the close: 2.1 bps on the last priceif it settled on the last price · 18 s before the close: 2.0 bps on the last priceif it settled on the last price · 16 s before the close: 1.9 bps on the last priceif it settled on the last price · 14 s before the close: 1.7 bps on the last priceif it settled on the last price · 12 s before the close: 1.6 bps on the last priceif it settled on the last price · 10 s before the close: 1.5 bps on the last priceif it settled on the last price · 8 s before the close: 1.3 bps on the last priceif it settled on the last price · 6 s before the close: 1.1 bps on the last priceif it settled on the last price · 4 s before the close: 0.9 bps on the last priceif it settled on the last price · 2 s before the close: 0.7 bps on the last priceif it settled on the last price · 0 s before the close: 0.0 bps on the last price
settled on the 60-second average (5- and 15-minute rule)if it settled on the last price
Computed from the rule and Bitcoin's median realized volatility over the period (26.2% a year); not a recorded path.

Hourly markets have no average: they settle on the Binance candle's close, so their last-minute moves come from the final trades of the hour. They were already the most decided of the three at T−60 s.

How often it still goes wrong

How often the favourite one minute before the close lost
0%2%4%6%8%10%5-minute · all favourites: 8.3%8.3%5-minute · favourites at 90¢ or more: 1.8%1.8%5-minute15-minute · all favourites: 4.8%4.8%15-minute · favourites at 90¢ or more: 0.8%0.8%15-minutehourly · all favourites: 3.9%3.9%hourly · favourites at 90¢ or more: 0.8%0.8%hourly
all favouritesfavourites at 90¢ or more
The order book's favourite one minute before the close
durationwindowsfavourite lostfavourites at 90¢+of which lostlost per night
5-minute87,4988.3%64,5471,130 (1.75%)14.9
15-minute29,1574.8%24,617204 (0.83%)2.7
hourly7,2913.9%6,38149 (0.77%)0.6
Lost per night = 90¢+ favourites that lost, over the four assets, per night of the period.

One minute out, the favourite still lost 8.3% of 5-minute windows, 4.8% of 15-minute windows and 3.9% of hourly ones. Even at 90¢ or more, 1,130 of 64,547 5-minute favourites lost (1.75%), about 15 a night across the four assets; at 15 minutes 204 of 24,617 (0.83%).

By half, the 5-minute rate of 90¢+ favourites that lost was 1.87% then 1.64%.

How it was measured

Windows: every resolved crypto Up or Down window, Aug 7 – Oct 21, 2026 (76 nights), with both snapshots: 123,946 windows. Outcomes are Polymarket's official resolutions.

Snapshots: halfway = the first snapshot past the window's midpoint; T−60 s = the first snapshot 60 seconds or less before the close. Price = the order book's mid on the Up side; the favourite is the side at 50¢ or more.

The √(1/3) factor is the standard deviation of the average of a Brownian path over an interval relative to its end point; it uses no data. The per-minute figures scale the median realized volatility at the open (1-minute candles, 24/7/365 year) to 60 and 20 seconds.

Limits

We keep two snapshots per window, not a second-by-second path of the last minute. What happens between T−60 s and the close is described here by its result, not by its path.

A snapshot's book price can rest on a slower price request when the live feed is quiet; the window record keeps no trace of it.

Windows overlap and the four assets move together: the rates are not independent draws, and small differences between durations should not be over-read.

Related

Market pages: Bitcoin 5m · Bitcoin 15m · Bitcoin 1h · Ethereum 5m · Ethereum 15m · Ethereum 1h · Solana 5m · Solana 15m · Solana 1h · XRP 5m · XRP 15m · XRP 1h
Research: How 5- and 15-minute crypto Up or Down markets resolve · When the order book says 70%, how often does it happen? · What “calibrated” means — and how to read it on our pages
All research → · Nightly track record →

Data analytics on Polymarket crypto markets · not financial advice · 18+. Figures from our own records of every window; outcomes are Polymarket's official resolutions.