Available public information does not establish how Jason Calacanis actually filled out his 2024 presidential ballot.

What we do know:

• In the June 29, 2024 All‑In episode “Presidential Debate Reaction, Biden Hot Swap?, Tech unemployment, OpenAI considers for‑profit & more,” Jason explicitly says: “This is breaking news. I am not voting for Biden. I’ve eliminated Biden as a possibility. I was waiting to see what happened last night.” (podcasts.happyscribe.com)
• Joe Biden subsequently withdrew from the 2024 race and endorsed Kamala Harris; Harris became the Democratic nominee against Donald Trump in November 2024, so Biden was not the Democratic candidate on the general‑election ballot. (en.wikipedia.org)
• In the post‑election All‑In episode “Trump wins! How it happened and what’s next,” the hosts joke about having all voted for Trump “twice” and in multiple swing states, but this is clearly tongue‑in‑cheek banter rather than a factual disclosure of each host’s ballot. (happyscribe.com)
• Coverage of the All‑In podcast and Jason’s political activity documents his endorsement of Dean Phillips in the Democratic primaries and his broader alignment with the show’s pro‑Trump, anti‑Biden shift, but none of these sources state whom he personally voted for in November 2024. (en.wikipedia.org)

Crucially, U.S. ballots are secret. Unless Jason himself publicly states “I voted for X” (or “I wrote in Joe Biden”), no external source can definitively confirm or deny whether he cast a vote for Biden—especially given that Biden was no longer the nominee and could only have been supported via an unusual write‑in or similar mechanism.

Because the election is long past but Jason has not disclosed his actual vote, we cannot determine with certainty whether he did or did not vote for Biden. The circumstantial evidence makes a Biden vote highly unlikely, but not provably impossible, so the prediction’s truth value remains ambiguous rather than definitively right or wrong.