UFC 300: Kayla Harrison vs. Holly Holm betting odds

Late Tuesday night, UFC president Dana White dropped a bombshell when he announced that Olympic gold medalist and two-time PFL champion Kayla Harrison had signed with the UFC.

The announcement didn't stop there though, he then revealed she'd be fighting Holly Holm in her UFC debut at UFC 300 on April 13.

Less than 24 hours later, sportsbooks are already taking bets on the upcoming fight.

According to DraftKings, Harrison is -310 favorite. Holm is a +250 underdog, which seems to reflect the way that MMA Twitter felt the fight might go.

One of the biggest "what ifs" for the fight will be if Harrison can make 135 pounds. In the past, she's competed at 155 and 145 pounds. She competed even heavier at the Olympics.

We included odds for the other already announced UFC 300 fights below.

UFC 300 opening odds

• Justin Gaethje (-225) vs. Max Holloway (+185) – for BMF title
• Zhang Weili (-345) vs. Yan Xiaonan (+275) – for strawweight title
• Charles Oliveira (+125) vs. Arman Tsarukyan (150)
• Kayla Harrison vs. Holly Holm (see above)
• Jiri Prochazka (+115) vs. Aleksandar Rakic (-135)
• Calvin Kattar (-110) vs. Aljamain Sterling (+130)
• Deiveson Figueiredo (-340) vs. Cody Garbrandt (+270)
• Bobby Green (-205) vs. Jim Miller (+170)
• Cody Brundage (+800) vs. Bo Nickal (-1400)

Odds refresh periodically and are subject to change.

There's still no main event announce for UFC 300, the 300th UFC PPV in the promotions history. Stay tuned for more updates on the card as they happen.