Prediction Market Trading Volume Hits $13.9B From September 1–7, 2026 as Kalshi Leads

Prediction market trading volume accelerated during the first week of September 2026, with the top CFTC-regulated exchanges recording $13.9 billion in combined volume between September 1 and September 7, 2026.

That was a 14.2% increase from the $12.2 billion recorded during the previous seven-day period.

The monthly numbers show a similar trend. During the 30 days leading up to September 7, the top 10 CFTC-regulated exchanges generated $49.5 billion in trading volume, up 14.3% from $43.3 billion during the preceding 30-day period.

Kalshi remained the dominant exchange, accounting for $11.8 billion of the seven-day total. Its 84.9% market share was slightly lower than the 86.4% recorded in the previous week, suggesting that competitors are beginning to capture a larger portion of the expanding market.

The biggest percentage move came from DKeX, DraftKings' prediction-market exchange. Its volume surged 609.9% to $226 million between September 1 and September 7.

College football was one of the major catalysts behind the increase. Kalshi's NCAA football volume jumped from $162 million to $647 million, while DKeX's sports volume increased 490.9%.

The numbers arrived just one day before NFL Week 1 began on September 9, 2026, giving prediction-market exchanges another major sports calendar to compete around.

Prediction Market Volume Increased 14.2% From the Previous Week

The seven-day period ending September 7 produced $13.9 billion in combined trading volume across the leading CFTC-regulated exchanges.

That compares with $12.2 billion during the previous seven-day period.

The difference is approximately $1.7 billion in additional trading volume in a single week.

The growth was not limited to the weekly measurement.

For the 30-day period ending September 7, combined volume reached $49.5 billion. During the preceding 30 days, the figure was $43.3 billion.

That represents an increase of approximately $6.2 billion.

The consistency between the weekly and monthly growth rates is notable.

The market was not simply boosted by one unusually large trading day. Activity was higher across the broader September measurement window as well.

Kalshi Generated $11.8 Billion Between September 1 and September 7

Kalshi continued to account for most prediction-market trading during the seven-day period.

The exchange recorded $11.8 billion in volume from September 1 through September 7, representing a 12.3% increase from the previous week.

Its share of the combined market was 84.9%.

That was down from 86.4% during the previous seven-day period.

The decline in market share does not mean Kalshi's volume decreased. The opposite happened. Kalshi added volume while the wider market grew at a slightly faster rate.

This distinction is important when assessing competition.

An exchange can increase its own trading volume while simultaneously losing market share if competing platforms grow faster.

That is exactly what the September 1–7 figures show.

Kalshi remains far ahead, but the other exchanges are growing around it.

Kalshi Set a $2.29 Billion Daily Volume Record on September 5

One of the most important dates in the week's data was Saturday, September 5, 2026.

Kalshi recorded a record $2.29 billion in trading volume on September 5 alone.

That single-day figure represented approximately 16.5% of the entire $13.9 billion traded across the tracked exchanges during the seven-day period.

The timing matters.

September 5 fell during the opening weekend of the college football season, creating a large concentration of sports-related trading activity.

The result provides another indication of how strongly prediction-market volume can respond to major sporting events.

Instead of activity being spread evenly across the week, large portions of trading can arrive around specific games, slates and events.

For prediction-market operators, that makes reliability particularly important.

When demand peaks around a fixed sporting schedule, an outage during those hours can potentially prevent traders from participating when interest is at its highest.

College Football Volume Jumped Nearly 300% on Kalshi

College football produced one of the largest category-level increases in the September 1–7 data.

Kalshi's NCAA football volume increased from $162 million to $647 million.

That is an increase of approximately $485 million.

In percentage terms, NCAA football volume rose by about 299%.

The category therefore moved from a relatively modest portion of Kalshi's football activity to a major source of sports volume within a single week.

Overall football volume on Kalshi increased 117% to $668 million.

The figures were heavily influenced by college football. NCAA football accounted for approximately $647 million of the $668 million football total.

Pro football, by comparison, represented about $20 million.

That split is particularly interesting because the NFL season had not yet begun during the September 1–7 measurement period.

NFL Week 1 was scheduled to begin on September 9, 2026.

The next set of weekly data will therefore provide an early comparison between the opening college football weekend and the beginning of the NFL season.

Tennis Remained Kalshi's Largest Individual Sport

Football recorded the fastest major growth among Kalshi's sports categories, but tennis remained the largest individual sport by volume.

Kalshi tennis volume reached $1.5 billion, up 20.2% during the seven-day period.

Baseball recorded approximately $668 million, with volume increasing 0.3%.

Basketball moved sharply lower, falling 90.2% to $11 million.

The difference between these categories illustrates how much prediction-market activity can depend on the sporting calendar.

Tennis provides a continuous schedule of tournaments and matches across different markets.

College football, meanwhile, can produce a dramatic increase when its season begins.

Basketball's much lower figure during this particular period demonstrates the opposite effect when fewer major events are available to generate trading interest.

Kalshi's $6.1 Billion Exotics Category Was Its Largest Market

Sports were not Kalshi's largest source of volume during September 1–7.

That distinction belonged to exotics.

Kalshi's exotics category generated $6.1 billion, representing 51.7% of the exchange's total volume.

The category increased 15.1% from the previous week.

Sports followed with $3.5 billion, while crypto generated $1.9 billion.

Crypto volume increased 1.4% to $1.9 billion.

Bitcoin contracts represented most of that activity, generating approximately $1.7 billion, while Ethereum contracts reached about $77 million.

Commodities were smaller but still grew 5.9% to $166 million.

Gold volume increased 11.3% to $100 million, while silver declined 21.0% to $22 million.

The breakdown shows that Kalshi's enormous volume is not dependent on a single category.

DKeX Volume Increased 609.9% During September 1–7

The fastest-growing major exchange during the period was DKeX.

Its trading volume reached $226 million between September 1 and September 7, representing a staggering 609.9% increase from the previous week.

The previous weekly figure was approximately $32 million.

DKeX therefore added roughly $194 million in volume in one week.

Its growth was concentrated in two categories.

Sports volume reached $122 million, up 490.9%.

Combo volume reached $105 million, up 826.3%.

The resulting product mix was almost evenly divided:

DKeX's rise into the top five CFTC-regulated exchanges is therefore one of the most significant developments in the September 1–7 data.

The percentage growth is especially striking because the exchange was starting from a much smaller base than Kalshi.

Combo Prediction Market Volume Reached $6.7 Billion

Combination contracts were another major growth area.

Across CFTC-regulated exchanges, total combo volume reached $6.7 billion during the seven days ending September 7.

That was up 19.4% from $5.6 billion during the previous seven-day period.

Combo volume therefore grew approximately 5.2 percentage points faster than overall prediction-market volume, which increased 14.2%.

Several exchanges recorded particularly strong growth.

Polymarket US combo volume increased 36.7% to $297 million.

Novig rose 26.1% to $87 million.

Underdog Exchange increased 38.3% to $67 million.

DKeX recorded the largest percentage increase, with combo volume climbing 826.3%.

The figures suggest that combination contracts are becoming a major component of prediction-market trading rather than a secondary product.

Polymarket US Recorded $1.1 Billion From September 1–7

Polymarket US ranked behind Kalshi with $1.1 billion in seven-day trading volume.

That represented a 14.9% increase from the previous week.

Sports generated $744 million, accounting for 71.1% of the exchange's volume.

Combo contracts generated another $297 million, representing 28.4%.

The product mix was therefore heavily concentrated in sports.

However, September 5 produced a notable difference between Polymarket US and several competing platforms.

Polymarket US volume increased only 6.5% from Friday, while Kalshi, Crypto.com, Novig and DKeX each recorded increases of at least 25%.

The source data linked the weaker increase to an outage during the college football slate.

That is more than a technical footnote.

Prediction markets operate around events that occur at specific times. If a platform is unavailable while a major game or event is underway, traders cannot simply recreate that lost trading window later.

Crypto.com Reached $248 Million in Weekly Volume

Crypto.com generated $248 million between September 1 and September 7, up 14.2%.

Sports represented the largest category at $156 million.

That gave sports a 63.1% share of the exchange's weekly volume.

Combo contracts generated $78 million, or 31.5%.

Crypto contracts accounted for approximately $13 million, representing 5.3%.

Sports volume increased 19.6%, while crypto contracts increased 17.9%.

Combo volume grew more slowly at 4.3%.

The result was a market still dominated by sports, even though Crypto.com's wider ecosystem has a strong connection to cryptocurrency.

Novig Volume Rose 23.9% to $229 Million

Novig recorded $229 million in volume during September 1–7, up 23.9%.

Its growth rate was higher than the overall market's 14.2% increase.

Sports generated $142 million, accounting for 61.9% of total volume.

Combo contracts contributed $87 million, or 38.1%.

The relatively high combo share makes Novig one of the more diversified exchanges in the September data.

Its weekly volume also placed it slightly ahead of DKeX in absolute terms, although DKeX's extraordinary growth rate was far higher.

Rothera Generated $178 Million With Sports Dominating

Rothera recorded $178 million in volume during the seven-day period ending September 7.

That was a 19.9% increase from the previous week.

The exchange's activity was overwhelmingly concentrated in sports.

Sports contracts generated $172 million, representing 96.6% of total volume.

Economics contributed approximately $4 million.

Elections generated approximately $2 million, with election volume falling 15.4%.

Rothera therefore had one of the most concentrated product mixes among the exchanges included in the September 1–7 figures.

Underdog Exchange Volume Fell 3.5% Despite Strong Combo Growth

Underdog Exchange recorded $91 million in weekly volume, down 3.5%.

The headline decline, however, masks a major change in its product mix.

Combo volume increased 38.3% to $67 million.

Sports volume fell 47.6% to $24 million.

As a result, combination contracts represented 73.6% of Underdog's total volume.

This is a useful example of why total exchange volume alone does not tell the entire story.

Underdog's overall volume declined, but one of its major product categories grew by more than one-third.

Prediction Market Exchange Volumes From September 1–7

The seven-day figures show a market where one exchange continues to dominate while several smaller platforms are recording substantial growth.

The most important number remains Kalshi's $11.8 billion.

The most important growth rate belongs to DKeX.

The strongest established competitor growth in the table comes from Novig at 23.9%.

Meanwhile, Polymarket US remained the second-largest exchange at $1.1 billion.

September 9 NFL Kickoff Creates the Next Major Test

The September 1–7 figures were released on September 8, 2026, immediately before the start of NFL Week 1 on September 9, 2026.

That timing creates a useful benchmark.

The first weekend of college football produced a dramatic increase in NCAA football trading.

Kalshi's NCAA football volume climbed from $162 million to $647 million.

DKeX sports volume increased 490.9%.

The next question is how prediction-market activity responds once professional football enters the data.

The NFL provides a long schedule of games, weekly storylines and individual markets. If the September 1–7 college football surge is representative of the wider sports opportunity, the September 8–14 period could produce another significant increase in trading volume.

That will also provide a better indication of whether the September growth represents a temporary seasonal spike or the beginning of a sustained expansion in sports prediction markets.

What the September 1–7, 2026 Data Means for Prediction Markets

The latest numbers reveal several important trends.

First, the market is growing.

The top CFTC-regulated exchanges generated $13.9 billion during September 1–7, up 14.2% week over week.

Second, Kalshi remains dominant.

Its $11.8 billion volume represented 84.9% of the tracked market.

Third, competitors are growing faster in several cases.

DKeX increased 609.9%, Novig rose 23.9%, Rothera increased 19.9% and Polymarket US climbed 14.9%.

Fourth, sports are becoming increasingly important.

College football produced a nearly 300% increase in NCAA football volume on Kalshi.

Fifth, combination contracts are expanding faster than the overall market.

Combo volume increased 19.4% to $6.7 billion, compared with 14.2% growth for total seven-day volume.

Finally, timing and infrastructure matter.

September 5 demonstrated the enormous volume that can arrive around major sports events. The same date also showed how an outage can potentially limit a platform's ability to capture that demand.

Prediction Market Outlook After September 7, 2026

The prediction-market industry entered September 2026 with strong momentum.

Between September 1 and September 7, the leading CFTC-regulated exchanges processed $13.9 billion in combined volume.

Kalshi alone accounted for $11.8 billion.

At the same time, DKeX's 609.9% weekly increase showed that smaller platforms can experience explosive growth when they gain access to major sports-driven demand.

The next measurement period begins with a major event of its own.

NFL Week 1 starts on September 9, 2026.

That means the September 8–14 data will be particularly useful.

It will show whether college football was simply responsible for a one-week surge or whether prediction-market trading volume can continue climbing as the NFL joins the sports calendar.

For now, the direction is clear.

Prediction-market volume is rising, sports are becoming a bigger source of activity, combination contracts are expanding rapidly, and Kalshi remains the dominant exchange by a considerable margin.