20VC: OpenAI Cuts Valuation to $1.25TRN | Public Market Meltdown: GOOG Loses $500BN in 12 Hours | DoorDash Buys Instacart for $17BN | Kalshi Raises $1BN and Cognition Eyes $80BN Valuation

Harry Stebbings runs through a packed week of tech and venture capital news. OpenAI reduces its fundraising target and valuation to $1.25 trillion amid a brutal sell‑off in AI stocks that wiped $500 billion from Google's market cap in one day. DoorDash announces a $17 billion acquisition of Instacart, while Kalshi raises $1 billion at a $40 billion valuation despite regulatory threats. Cognition eyes an $80 billion valuation, and an AI law firm bids for a collapsed legal giant.