Shares of Virgin Galactic, the space tourism venture founded by Richard Branson, are plunging after the British billionaire said he has no plans to invest more money in the company as he says it has “sufficient funds” already. As of the 9 a.m. ET market open on Monday, Virgin Galactic stock was down 16%, trading at less than $2 per share. Virgin Galactic has had a landmark year, flying its first customers to the edge of space after years of waiting. But the company has also been in a state of flux, having just laid off about 20% of its staff and working to introduce a new line of suborbital spacecraft that will ... (full story)