Sunday, October 18 set new highs in EventTracker’s available daily records. Seven exchanges reported $5.43 billion in notional trading volume, while across our broader coverage we tracked 50,339 markets during the day. Both exceeded October 11: volume rose 4.2 percent on the same seven-exchange basis, and the market count rose by 651, or 1.3 percent.
The weekend was bigger too. Saturday, October 17 had already set a volume record at $5.42 billion. Sunday finished slightly higher, bringing the two days to $10.84 billion, compared with $10.01 billion over October 10–11 on the same basis.
Most of the reported volume went through Kalshi. It recorded $4.11 billion, about 76 percent of the seven-exchange total. Polymarket US added $737 million, followed by Novig and Nadex. On Kalshi, $2.90 billion, about 71 percent of its total, came from combos: single contracts that tie several outcomes together. Here, notional volume measures contracts at their settlement face value; it is different from the cash people paid to buy them.
October 18 continued a run of rising Sunday totals: $3.82 billion on September 20, $4.19 billion on September 27, $4.79 billion on October 4, $5.21 billion on October 11 and $5.43 billion on October 18. Each figure uses the same official-report basis. Beneath those peaks, Kalshi’s median daily volume rose from about $565 million in May to $2.59 billion over October 1–18.
Official daily notional volume across seven exchanges, by each source’s labelled trading or report date, August 4–October 18, 2026. October 18 reached $5.43 billion, above October 11’s $5.21 billion on the same basis. August 26 and October 7 are gaps because Polymarket US reports are missing. The chart starts August 4 to keep Novig’s volume definition consistent.
The other record is about breadth. We tracked 50,339 markets across 29 venues during October 18, up from 49,688 across 28 venues a week earlier. Since April 29, we have recorded 870,061 distinct market listings through October 18. A question listed on two venues counts separately on each. Some of this growth comes from the markets themselves, and some from EventTracker adding venues and reading deeper into each one. These are records for the universe we observe.
Total market listings observed across EventTracker venues during each UTC day, April 29–October 18, 2026. October 18 reached 50,339 across 29 venues, compared with 49,688 across 28 venues on October 11. Coverage expanded during this period; a question listed on two venues counts separately on each.
If you are new here, EventTracker brings prediction markets together on one board. Kalshi, Polymarket US and Nadex sit alongside crypto-native venues such as Polymarket, Limitless, Outcome.xyz and Pascal, and sports exchanges such as Novig and ProphetX. You can compare the same question across venues, see what it costs to trade, follow large wallets and read the news that moves prices, without keeping a dozen tabs open.
EventTracker is independent. We take no bets, hold no money and carry no affiliate links, and no venue pays us for coverage or placement. Our job is to measure the market honestly and give you enough context to understand the figures. October 18 is the new high in our available records. We will measure the next one with the same care.
Tal Ayalon
eventtracker.ai
Figures retrieved October 19, 2026. Volume totals use official daily notional data from Kalshi, Polymarket US, Novig, Nadex, UDX, Rothera and ProphetX, by each exchange’s reported trading or business date. October 11 is recalculated on this basis. Market counts cover listings observed during each UTC day, not simultaneous live listings. Records refer to the available series beginning April 29, 2026; coverage has expanded and some historical reports are missing. Nothing here is investment or wagering advice.