Regulators have long warned that the end of rock-bottom interest rates could cause sudden crises in unexpected corners of global finance. So when Silicon Valley Bank surprised the market with plans for a share sale and a $1.8 billion loss on securities sales, investors were left wondering if its problems were isolated or the harbinger of a broader funding crunch in credit markets. Major banks are much better capitalized and far less leveraged than they were in the lead-up to the global financial