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The sportsbook and fantasy product of the Underdog brand
Visit Underdog Sportsbook →Underdog Sportsbook welcome bonus in United States
Context for United States: The United States regulates online gambling state by state, not nationally, so an offer on this page is only claimable if you are physically located in a state where that operator holds a licence - most US states license no online casino or poker at all. Check the state, not the country. The Multi-State Internet Gaming Agreement lets state-regulated poker operators pool players across state lines; as of April 2026 its members are Nevada, New Jersey, Delaware, Michigan and Pennsylvania. Nevada also requires an online operator to partner with an in-state casino, keeping its poker market small. SWEEPSTAKES CASINOS ARE A SEPARATE, RAPIDLY CLOSING CATEGORY: dual-currency sites (Gold Coins to play, Sweeps Coins redeemable for cash) are being banned outright, not regulated, in a growing list of states including Montana, Connecticut, New Jersey, New York, California, Nevada, Maine, Indiana and Oklahoma. Sources disagree on the exact total, so check your own state rather than any single figure - and note these laws can reach payment processors and affiliates too, not just the operator.
Here is the current Underdog Sportsbook welcome offer for players in United States. Bonus terms change and are set by Underdog Sportsbook for each market — always confirm the live offer on its own site. See every licensed betting site in United States →
Pros
- A well-funded, independently confirmed company backed by major investors (BlackRock, Mark Cuban)
- A real play-and-get offer worth 10x the initial stake
- Low USD 5 stake to unlock the full offer
Cons
- Not available in several major US states
- Fantasy-style legal framework differs from traditional sports betting — read the terms carefully
Our verdict
Underdog Sportsbook is operated by Underdog, founded 2020 by Jeremy Levine, Brandon Stakenborg and Trevor John, valued at $1.225 billion (Series C, early 2025) with backers including BlackRock and Mark Cuban - independently confirmed on a second source. It is active in the US, excluding Maryland, Michigan, New Jersey, New York, Ohio and Pennsylvania, offering new players who play USD 5 a return of USD 50 in bonus entries, valid 14 days.
How we rated it
Bonuses & value (18%)8
A real play-and-get offer worth 10x the initial stake.
Trust & licensing (27%)8
A real positive: a well-funded, named company (founded 2020, $1.225 billion valuation, backed by BlackRock and other major investors), independently confirmed, with a genuine regulated sportsbook launch in North Carolina.
Sportsbook (36%)7
The sportsbook/fantasy product of the Underdog brand, excluded in several US states.
Customer support (18%)7
No major documented complaint pattern found.
Quick facts
| Company | Founded 2020; $1.225 billion valuation (Series C); investors include BlackRock, Mark Cuban |
| Markets | United States (not MD, MI, NJ, NY, OH, PA) |
| Welcome bonus | Play USD 5 get USD 50 in bonus entries |
| Validity | 14 days |
How we verified this
Two independent domains corroborate the core facts, resolving the earlier single-source flag. goal.com documents the welcome offer terms (play USD 5 get USD 50 in bonus entries, valid 14 days) and state exclusions (Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania). sacra.com independently confirms the company's founding (2020, by Jeremy Levine, Brandon Stakenborg and Trevor John), its Series C funding ($100M, valuing it at $1.225 billion) with backers including BlackRock and Mark Cuban, and its March 2024 sportsbook launch in North Carolina.
Where Underdog Sportsbook is licensed
Underdog Sportsbook appears on the official register in 1 countries. Highlighted countries have a full local review — pick yours for its welcome bonus and licence details.
North America (1)
About Underdog Sportsbook
Underdog Sportsbook is the sportsbook/fantasy product of Underdog, a well-funded company (founded 2020, $1.225 billion valuation) that launched a regulated sportsbook in North Carolina in March 2024, offering new players a real, sizeable play-and-get bonus.
Underdog Sportsbook FAQ
Is Underdog Sportsbook safe and legit?
Yes — Underdog Sportsbook is operated by Underdog, a well-funded company (founded 2020, $1.225 billion valuation, backed by BlackRock and Mark Cuban), independently confirmed. It is active in the US, excluding several states. No major scandal was found during this research.
What is the Underdog Sportsbook welcome bonus?
Play USD 5 and get USD 50 in bonus entries, valid 14 days.