Y Combinator, a Silicon Valley kingmaker, is advising its portfolio founders to “plan for the worst” as startups across the globe scramble to navigate a sharp reversal after a 13-year bull run. The investment firm — whose early backings include investments in Dropbox, Coinbase, Airbnb and Reddit — this week suggested startups cut their expenses and focus on extending their runways within the next 30 days. For those who don’t have the runway to “reach default alive,” YC is strongly suggesting ...