Stablecoin issuer Tether, flush with cash, has a new pastime: investing in other companies, including in Eight Sleep, which makes a popular smart mattress.Tether is going beyond the usual corporate VC playbook of investing in nascent upstarts using its technology or in direct business partners. Instead, it seems to be putting its piles of cash to work in creative ways amid the currently depressed cryptocurrency markets.“Tether has more money than it knows what to do with,” a crypto industry inve...