"The last three months of 2021 really put an exclamation point on what has been relentless growth all year," said Ian St. Clair, lead analyst for PlayColorado.com. "Coloradoans continue to wager at a pace on par with more populous states, and it is still a market that has not yet fully matured. The state's sportsbooks are in a really good place."

Colorado's online and retail sportsbook took in $461.4 million in wagers in December, up 62.6% from $284.6 million in December 2020, according to data released Monday by the Colorado Division of Gaming. December's handle — which included $454.9 million in online bets, or 98.6% of the total handle — extended a hot streak that included $475.4 million in November and a record $491.5 million in October.

Bettors fared better in December after sportsbooks won a record-shattering $36.8 million in gross revenue in November. But Sportsbooks still grossed $24.7 million from December's bets, which was up 44.2% from $17.2 million in December 2020. Net sports betting proceeds fell to $5.3 million from $5.7 million in December 2020, well short of the record $19.3 million in November. The month's win yielded $770,370 in state taxes, breaking a two-month streak of tax revenue greater than $1 million.

The first full year of legal sports betting in Colorado brought explosive growth throughout. In 2021, Colorado sportsbooks generated:

• $3.85 billion in online and retail wagers, up from $1.2 billion in 2020. 2021's handle will place Colorado sixth in betting volume for the year among legal sports betting jurisdictions in the U.S.


• $3.79 billion in online wagers, which accounted for 98.4% of all bets, the highest rate in the U.S. The online handle was up from $1.1 billion in 2020.


• $250.1 million in gross revenue, up from $75.8 million in 2020.


• $11.7 million in state taxes, up from $2.96 million in 2020.

"By nearly every metric Colorado is hitting above its weight class, with the exception of the tax revenue sports betting generates," said Eric Ramsey, analyst for the PlayUSA.com network, which includes PlayColorado.com. "Importantly, tax revenue ramped up at the end of the year, which is a positive development. That could continue as the market expands and sportsbooks begin to taper their promotions."

One reason why sportsbooks were able to finish the year on a high note is the increasing popularity of basketball betting, particularly the NBA. Pro football was the hottest ticket in December with $136.5 million in wagers, down slightly from $140.3 million in November. But pro basketball was just behind with $125.5 million in bets, up from $124.7 million in November.

In the end, it was pro basketball that drew the most bets in 2021 with $958 million in wagers. Meanwhile, pro football took in $689.2 million in 2021.

"Interest in the Nuggets combined with the Broncos' struggles contributed to the leveling of interest in football and basketball in December," said Ian St. Clair, lead analyst for PlayColorado.com. "Football is popular in every legal U.S. market. But a hallmark of the highest volume U.S. markets is that the NBA, with its 82-game regular season and long postseason, tends to be a more consistent bet producer than the NFL. Colorado is clearly fitting into that pattern."