Claude’s Fable 5 just solved an 87-year-old math problem, and it matters for bitcoin

But the larger pull is simpler: AI is where the speculative money and investors’ attention are now going. The capital that once chased crypto is now chasing compute, chips and model builders, and every leap in what these systems can do widens that appeal.

Each result like Fable’s finding of the Jacobian conjecture strengthens the case for pouring capital into AI, and poses a difficult conundrum for crypto investors: Why hold a token that trades as a sidecar to the AI cycle when someone can own the vehicle itself?

AI’s capability curve is steep, and the steeper it gets, the more of the market’s risk appetite it draws away from everything else, crypto included.

What the problem actually was

Think of a machine that takes two numbers and gives back two new numbers, using only adding and multiplying. The question, first asked in 1939, was whether the machine can always be run backward: given only its answer, can the original two numbers be recovered every time?

Mathematicians had a quick way to check whether a machine looked reversible. The Jacobian conjecture said that if a machine passed that check, it should always be reversible.

For 87 years, nobody could prove it was true, and nobody could find a machine that broke the rule.