Investors have been taking advantage of low interest rates and discounted prices to buy run-down foreclosure properties, sometimes 10 or so at a time. They fix up the properties enough to be rented until the market turns, which could take years. When the time is right, the investor puts the finishing touches on the improvements and hopefully sells for a profit.
This can be a risky strategy for an inexperienced homebuyer. It's hard to compete with investors who make all-cash offers. Investors usually have a team of contractors who can do the fix-up work. If they're working on several properties at once within close proximity of one another, it's more economical than fixing up one property at a time.