At first, everyone thought it was just a weed joke. “Am considering taking Tesla private at $420,” Elon Musk tweeted Tuesday afternoon. “Funding secured.” But it didn’t take long before that assumption went up in smoke. The news sent shockwaves through the financial system, with Tesla’s shares finishing up 11 percent. Less than 24 hours later, experts are still scratching their heads, wondering how Musk could pull off what could be the largest management-led buyouts in history. Taking a roughly $60 billion company private is a tall order, even for a CEO with a reputation for defying the odds.