When the United States began legalizing sports betting state by state after a landmark Supreme Court ruling in 2018, the question was how long it would take for American operators to become globally significant. 

Eight years later, the answer is in the market capitalization data.

The visualization above ranks the market cap of key companies in the online gambling industry.

The data comes from OGQ-Magazine’s Online Gambling Quarterly, gathered as of April 2026.

NOTE: Market cap is the total value of a company’s outstanding shares of stock. That is, what it would cost you if you were to buy up all of its outstanding shares at the current share price.

TL;DR

• Four U.S.-focused gambling operators (DraftKings, MGM, Caesars, and Rush Street) appear in the Europe top ten by market cap, with a combined value of approximately £23.83 billion 
• Flutter Entertainment leads the entire industry at £14.06 billion, with the top four companies alone holding just over half the combined market value of all 31 companies in the dataset.

ALSO READ: Kashi, Polymarket Dominate as Prediction Markets Log 28.5 Million Weekly Bets

Who’s at the Top?

Flutter Entertainment, headquartered in Ireland, holds a market cap of £14.06 billion.

Flutter owns FanDuel, the dominant US sports betting platform, alongside Paddy Power, Betfair, and Sky Bet in Europe. 

It is global in structure, but its FanDuel business in the United States is widely credited as a primary driver of its valuation.

Even the industry’s undisputed leader is, in significant part, an American story.

The US Four and What Separates Them

DraftKings at £8.68 billion is the highest-valued pure-play digital sports betting company in the record. 

It has no physical casinos and no legacy European business. 

Its valuation is a direct read on investor confidence in the US digital betting market. 

MGM sits fourth at £7.09 billion, combining its physical casino empire with its BetMGM digital operation. 

Caesars follows at £4.08 billion in sixth place, and Rush Street (operator of BetRivers) sits eighth at £3.98 billion.

The four together account for more combined value than the next 21 companies in the dataset.

ALSO READ: Largest Airlines by Market Cap

Cliff Between the Tiers

The top ten ends with FDJ, the French national lottery operator, at £3.66 billion.

The 11th company, Penn National, sits at £1.49 billion (a drop of more than £2 billion in a single step). 

Below Penn National, the list descends steadily through Betsson (£1.33bn), Tabcorp (£1.19bn), and a long tail of smaller operators and affiliates, ending at Scout Gaming’s £3 million. 

The ratio between Flutter at the top and Scout Gaming at the bottom is roughly 4,700 to one.

ELI5

Since the U.S. legalized sports betting in 2018, four American gambling companies have grown large enough to rank among the ten most valuable in the European market. 

The most valuable gambling company overall is Flutter, an Irish firm that owns FanDuel in the US. The industry is worth about £77 billion in total, but most of that value sits with just a handful of companies at the top.

Source: 

OGQ-Magazine’s Online Gambling Quarterly