What Is Underdog?

Where UDX came from

Underdog, the daily-fantasy company, spent ten months as a middleman before it became a venue. Starting in September 2025, it offered prediction markets inside its own app as an intermediary — taking customers' orders and passing them to third-party exchanges, including Kalshi and Crypto.com, for matching. Every one of those orders was demand it originated and revenue it handed to someone else's exchange.

In March 2026, Underdog closed that gap by acquiring Aristotle Exchange, inheriting a registered Designated Contract Market — the venue that lists and matches contracts — and a Derivatives Clearing Organization, the entity that settles them. Combined with Underdog's existing registration as a Futures Commission Merchant, the broker role that carries customer orders, that's reported to make it the first sports company holding all three pieces of the license stack. The exchange trades under the brand UDX; the legal entities are still Aristotle Exchange DCM, Inc. and Aristotle Exchange DCO, Inc., d/b/a "UDX." It self-certified its first seven contract templates with the CFTC on July 15, 2026 and opened to the public three days later, on July 18, 2026.

Buying a licensed venue instead of applying for one is the standard route into this market now. Polymarket did it to create its regulated U.S. arm. Rothera did it with the exchange formerly known as LedgerX. A CFTC designation is slow to earn and comparatively fast to acquire, and each acquirer has concluded that eighteen months of regulatory process is worth more than the purchase price.

What separates Underdog is the order of operations. Rothera is wholesale infrastructure that sits behind brokers and has to persuade them to route to it. ProphetX built an exchange and then had to go find the two-sided liquidity to fill it. Underdog inverted that: it spent ten months generating order flow for someone else, then bought the place to send it. That's a real structural advantage rather than a marketing line — and it's also the thing worth watching, since the real question was never whether UDX could find volume, but how much of Underdog's existing activity would migrate onto its own book, and how fast.

How UDX contracts work

The mechanics, per the CFTC filings, are conventional. Contracts carry $1 notional and settle at $1 or $0 — a standard binary contract, so the price reads straight through as the market's implied probability. They trade between $0.001 and $0.999, and expiration is set at 10:00 AM ET — all times in the contracts are Eastern.

One detail is worth flagging for anyone used to other venues: there is no separate "No" contract. Long and short are two sides of the same instrument, so taking the "No" position is simply selling. If you're scanning a UDX order book looking for the paired Yes/No listings Kalshi displays, that's why you won't find them — the other half is the sell side of the book you're already looking at.

Underdog's public data feed is also unusually granular. Alongside a standard end-of-day summary, it publishes a record of individual trade fills — a level of detail most exchanges in this category don't expose — and reports contract counts as genuinely fractional quantities rather than whole numbers.

The $6.5 billion figure, and what it actually measures

Coverage of the UDX launch has leaned on a headline number: roughly $6.5 billion in prediction-market volume. It's worth being precise about what that figure counts, because the natural reading of it is wrong.

That total is Underdog's cumulative notional prediction-market volume since September 2025, earned as an intermediary routing customer orders to other exchanges. Most of it predates UDX existing as a live venue, and almost none of it traded there. It measures Underdog's reach as an operator across venues — it says nothing about the size of its own exchange.

The distinction matters for anyone comparing platforms. Underdog-the-distributor and UDX-the-exchange are two different things with two different volume figures, and only one of them is an exchange statistic. The $6.5 billion belongs to the distributor, not the venue, and the number simply travels without that caveat attached.

What UDX lists

Seven contract templates were self-certified with the CFTC on July 15, 2026. In the launch window that followed, three were observed trading, all baseball: moneyline (which team wins), spread (whether a team wins by more than a given margin), and total (whether combined runs finish above a given line). The remaining filings cover basketball equivalents — filed but not yet observed trading — and one open-ended "entity outcome" template whose structure hasn't been publicly described. Filing a template and listing a market are different acts; UDX opened as a baseball venue, whatever it lists later.

UDX also ran a pilot before it announced. Trades appear in the public record on July 17, 2026 — a day ahead of the public launch — confined to a single game and totaling around a thousand contracts across fewer than a hundred trades: a controlled live test, not a market. The launch date itself, and the day after, published no trades at all — genuine pre-volume rather than a reporting gap. Activity then arrived at once: the exchange's first substantial day, July 20, 2026, covered 16 games and carried roughly 28 times the pilot's contract count.

Those are opening-week facts about opening week — they describe how a venue switched on, not a level it holds or a rate it sustains. One further caution applies whenever these numbers meet another exchange's: contracts is a face-value count of contracts traded, while notional is price-weighted dollars. Venues in this category report on different conventions, so a contract count on one exchange and a dollar figure on another aren't comparable quantities.

Where UDX sits in the field

Underdog was the fourth CFTC-regulated venue to arrive in 2026, after Rothera, ProphetX and DKeX. Read together, they're less a series of individual launches than one structural shift: federally regulated event-contract exchanges are becoming ordinary infrastructure, and the companies building them are increasingly consumer brands rather than financial ones.

Within that group, each has picked a different flank. Rothera is neutral wholesale plumbing for brokers. ProphetX is a single-category exchange competing on market structure. DKeX and Underdog both arrive attached to established consumer sports businesses with audiences already in hand. Underdog arrived last of the four, and its case rests most explicitly on owning its own distribution. Through that entire wave of launches, Kalshi held the volume lead by a wide margin, and a first week of trading doesn't move a gap that size. For the two best-known venues head to head, see Kalshi vs. Polymarket.

Company & funding

Private, VC-backed, founder-led (CEO Jeremy Levine). The exchange itself operates under the CFTC-registered legal entities Aristotle Exchange DCM, Inc. and Aristotle Exchange DCO, Inc. — acquired by Underdog in March 2026, now doing business as "UDX." No public financials or IPO.

• Employees: ~500–600 (aggregator estimates conflict: 501–1,000 / 588 / 593)Needs verification (2026-06)
• Nearly four million customers nationwide; the fourth most-downloaded sports gaming app in the US as of March 2025 (Underdog/Businesswire, Series C release).
• ⚠️ Since Sept 2025 Underdog has processed ~$6.5B in notional prediction-market volume as an intermediary routing to other venues (per DeFi Rate/InGame reporting) — this is NOT UDX exchange volume and should never be cited as such.
• Reportedly laid off ~30 staff in a March 2026 restructuring, about a year after crossing a $1B valuation (Sportico, 2026).
• First sports-gaming operator to hold the complete prediction-market license stack: DCM + DCO + registered Futures Commission Merchant (FCM), per Underdog's own July 2026 launch release.

Funding

Total raised over $140M disclosed across 4 rounds (2020 seed undisclosed)No Series D or later round found as of this pass (2026-07) — Series C (March 2025) is the most recent disclosed round for Underdog-the-company. These are Underdog's corporate funding rounds; UDX itself has no separate funding — it's a product line financed off the parent's balance sheet plus the acquired Aristotle Exchange DCM/DCO entities. An earlier 2020 seed (led by Bryan Rosenblatt) was undisclosed and is shown in the timeline rather than itemized here.

Timeline

Regulatory status

UDX operates under the CFTC registrations of Aristotle Exchange DCM, Inc. and Aristotle Exchange DCO, Inc. — acquired by Underdog in March 2026 rather than built from scratch. Underdog also holds Futures Commission Merchant (FCM) registration, giving it what its own launch materials call "the complete prediction market license stack." Like Kalshi, Rothera, DKeX, and ProphetX, UDX's contracts are self-certified with the CFTC under the standard Commodity Exchange Act process — the agency does not pre-approve each product, it can only object after the fact. UDX self-certified its first 7 event-contract templates on July 15, 2026 and began trading July 17, 2026.

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