What is the fine-grained topic of the following text: For those who already own a modest piece of the rock, and who held on through the bad years, rising real estate values also yield a once-in-a-lifetime bonanza, a hike in net worth that trickles down to the rest of the family, providing a nice cushion against an otherwise fickle economy...The people directly in harm's way, however, are those clinging to the lower rungs of the economic ladder: renters who never came close to raising a down payment for their own home, let alone a sparkling new condo with granite counters and backsplash. Only return the topic.
The impact of rising real estate values on different economic classes