Kalshi Posts Record $2.9B Week on NCAA Basketball Tournaments as Polymarket Dips
The weekly whole dipped barely, however the extra telling story is Kalshi and Polymarket moved in reverse instructions this week, pushed by unrelated forces. Kalshi posted $2.93B in notional quantity, its highest single-week whole within the DeFi Rate monitoring interval, whereas Polymarket pulled again to $2.34B. Together they totaled $5.28B for the week of March 9–15, down modestly from $5.35B the prior week, as whole trade quantity throughout all tracked platforms hit $5.76B.
- Kalshi: $2.93B weekly quantity (+2.7% WoW)
- Polymarket: $2.34B weekly quantity (-6.1% WoW)
Across all tracked platforms, 44.4 million transactions have been recorded for the week. The DeFi Rate prediction markets tracker has the total breakdown, together with open curiosity by platform and class. Kalshi’s positive factors got here virtually solely from convention championship basketball — 4 faculty video games cracked its weekly prime 10 forward of Selection Sunday — whereas Polymarket’s most lively market was a Federal Reserve rate decision that drew $141.9M over the earlier seven days.
Some key takeaways from final week:
- NCAA basketball video games appeared in Kalshi’s prime 10 for the primary time, with Wisconsin-Michigan main at $9.2M as March Madness trading will get able to ramp up.
- Three 2028 presidential markets on Polymarket mixed for $121.5M, a significant quantity driver with the election over two years out.
- The Oscars helped drive WoW surges in Entertainment buying and selling quantity on each Kalshi (326%) and Polymarket (96%), although the class stays small in comparison with Sports and Crypto class volumes on each platforms.
Kalshi vs. Polymarket pattern
Kalshi prolonged its run of majority market share relative to Polymarket, including $76.6M WoW (+2.7%) whereas Polymarket dropped $152.1M (-6.1%). The divergence traces cleanly to the sports activities calendar. Conference championship week with the Big Ten, SEC, Mountain West, and different main tournaments operating concurrently delivered a wave of short-duration, high-liquidity basketball markets that play on to Kalshi’s power in home sports activities outcomes.
On transactions, Polymarket nonetheless leads: 24.7 million trades versus Kalshi’s 19.7 million. Both platforms shed transactions WoW (Kalshi -1.5%, Polymarket -6.1%) that means this week’s quantity strikes got here from bigger particular person positions, no more exercise. That reads clearly within the common wager sizes: Kalshi merchants averaged $148.61 per commerce (+4.2% WoW) whereas Polymarket got here in at $95.01, basically flat. The 1.6:1 ratio in common wager measurement has been a constant characteristic throughout current weeks, reflecting meaningfully completely different participant conduct. Polymarket is attracting higher-frequency, smaller-bet merchants whereas Kalshi skews towards bigger particular person positions on a per-trade foundation.
Kalshi quantity
Polymarket quantity
Kalshi tx
Polymarket tx
| Week of | Kalshi vol. | Poly vol. | Kalshi WoW | Poly WoW |
|---|---|---|---|---|
| Feb 2 | $2.80B | $1.92B | — | — |
| Feb 9 | $2.43B | $1.88B | -13.2% | -1.9% |
| Feb 16 | $2.59B | $1.82B | +6.8% | -3.2% |
| Feb 23 | $2.73B | $2.40B | +5.3% | +31.9% |
| Mar 2 | $2.86B | $2.50B | +4.7% | +4.0% |
| Mar 9 | $2.93B | $2.34B | +2.7% | -6.1% |
Market share settled at 55.6% Kalshi, 44.4% Polymarket on a head-to-head foundation, persevering with a pattern that carried from NFL right into a dense NBA and NCAA basketball schedule. The structural query heading into Q2 is whether or not Kalshi can maintain majority share as soon as the faculty basketball season ends and the NBA heads into playoffs mode in April.
Kalshi vs. Polymarket metrics: Week of March 9-15
| Metric | Kalshi | WoW Δ | Polymarket | WoW Δ |
|---|---|---|---|---|
| Volume | $2.93B | +2.7% | $2.34B | -6.1% |
| Transactions | 19,747,251 | -1.5% | 24,671,808 | -6.1% |
| Avg. wager measurement | ~$148.61 | +4.2% | ~$95.01 | ~flat |
| Market share | 55.6% | — | 44.4% | — |
Source: DeFi Rate. Week ending March 15
Polymarket US highlights
Polymarket US stays sports-only and at present basketball-focused. All 10 highest-volume markets final week have been NBA or faculty basketball recreation outcomes. The prime market — Sacramento Kings vs. Los Angeles Clippers — drew $590.2K; the underside of the highest 10 got here in at $341.1K (Golden State Warriors vs. Utah Jazz).
The quantity scale hole between Polymarket US and both Kalshi or world Polymarket stays large: the highest US market this week represents roughly 1/twenty third the quantity of the comparable Kalshi NBA recreation.
Polymarket US weekly snapshot
| Metric | Mar 9–15 | Mar 2–8 | WoW Δ |
|---|---|---|---|
| Volume | $5.9M | $5.9M | ~flat |
| Active markets | 488 | 354 | +37.9% |
| Open curiosity | $1.1M | $884.4K | +24.4% |
| Top market | Sacramento vs. LA Clippers | OKC vs. NY Knicks | — |
| Top market quantity | $590.2K | $532.9K | +10.7% |
Source: DeFi Rate prediction markets tracker. Week ending March 15
While total quantity was flat, lively markets up 37.9% to 488 and open curiosity up 24.4% to $1.1M each recommend the platform is increasing its market protection even as uncooked quantity holds regular.
Polymarket US prime 5 markets by quantity, final 7 days
US
| # | Market | Leading | Volume (7d) |
|---|
