Kalshi and Polymarket account for 1.33m of 2.8m NFL betting app downloads in Week 2

NFL betting app downloads rose 28% year over year in Week 2 of the NFL season, with Kalshi and Polymarket together accounting for 1.33 million of the 2.8 million recorded in the week ending 21 September. The figures come from Sensor Tower data quoted by Citizens, as reported by Legal Sports Report.

For affiliates and operators, the data shows prediction-market apps taking a large share of NFL betting app downloads while traditional sportsbooks face tougher comparisons.

What happened

After the 2.8 million downloads recorded in the week ending 21 September, cumulative download growth for the opening two weeks of the season stood at 19%, according to the Sensor Tower figures cited by Citizens. Kalshi recorded 706,000 downloads in the week and Polymarket 624,000. Their combined downloads made up approximately 47.5% of the weekly figure.

Over the first two weeks, the tracked operators rank as follows:

Operator	Downloads, first two weeks
Polymarket	1.37 million
Kalshi	1.31 million
DraftKings	805,000
FanDuel	502,000

Citizens linked the continued weakness of traditional sportsbooks partly to difficult year-over-year comparisons. It also noted that this season has no new state launches or comparable customer growth of the kind that lifted downloads in the previous season.

Pricing. Citizens also looked at pricing in NFL Week 2 moneyline and totals markets, using 30 observations collected on 18 September. Kalshi's implied vig averaged 4.22%, compared with 4.43% for FanDuel and 4.50% for DraftKings. These figures exclude any Kalshi transaction fees.

The gap did not carry over to parlays. A separate set of 15 observations covered combinations of a favourite with the Over, and the average implied vig for Kalshi there was 26.4%. DraftKings averaged 23.9%. According to Citizens, Kalshi's combo pricing also ran 6% above FanDuel's before transaction fees.

Volume. Citizens reported that over the preceding 30 days, combos on Kalshi produced $26 billion in volume. This accounted for 53% of the platform's total, whereas the average across the previous 90 days was 44%. Separately, TickerTracker data showed Kalshi recorded its first $3 billion day. On, volume was approximately $2.82 billion, a 14.6% rise on the previous week.

The report notes that these are notional trading volumes, which include trading over and above the sum customers first stake, so they cannot be compared directly with traditional sportsbook handle.

Why it matters

Affiliates and operators could need to check how their acquisition and install benchmarks account for prediction-market apps, which now make up almost half of weekly NFL betting app downloads in this dataset. Comparing sportsbook install trends against a total that includes Kalshi and Polymarket could overstate or understate performance, depending on the channel.

The pricing data also gives sportsbooks a more specific picture of where Kalshi is and is not competitive. Its average implied vig was lower than at DraftKings and FanDuel on the sampled moneyline and totals markets, but higher on the parlay sample. As combos grow as a share of Kalshi's volume, parlay pricing is likely to become a more important point of comparison for operators.

Citizens bases its view on customer-wallet analysis; it suggests that growth in prediction-market use could be enlarging the total wagering market instead of just pulling business away from sportsbooks. If that holds, operators could face competition for attention and spend without necessarily losing existing customers. The notional-volume caveat means volume comparisons with sportsbook handle should be treated with care.

What's next

Citizens anticipates that growth in traditional sportsbook handle will pick up later in the year, once operators get beyond tough comparisons. Week 3 of the NFL season begins.