Tech billionaires threaten to flee California over proposed 5% wealth tax

Silicon Valley's wealthiest residents are once again threatening to leave California, this time over a proposed state wealth tax that tech founders warn could fundamentally reshape where innovation — and capital — call home.

The proposal, backed by the Service Employees International Union–United Healthcare Workers West, would impose a one-time 5% tax on the assets of California residents worth more than $1 billion.

Supporters say the revenue could help offset federal funding cuts for healthcare...