SAN FRANCISCO — The government has been sniffing around hedge funds for years and now, like a dog that’s found where the bone is buried, it has started digging.

Last month, authorities charged six in a vast insider trading ring involving New York hedge fund Galleon Group. Last Friday, the Securities and Exchange Commission charged the former executives of two San Francisco funds with another insider trading conspiracy. And on Tuesday, Alexander Trabulse, a Colma hedge fund manager who authorities say bilked investors out of $8.3 million, pleaded guilty to mail fraud charges.