The belief in Detroit’s imminent revival has spread far beyond Dan Gilbert and the skyscrapers of downtown. Out in the neighborhoods, there is a legion of mini-Gilberts, longtime Detroiters and recent transplants alike, who have united around a conviction that the city has fallen as far as it can go — that the time to buy in is at hand. Just a couple of years after Detroit slid into what the national news media incessantly called a “post-apocalyptic” collapse, the city now teems with a post-post-apocalyptic optimism. When I visited this spring, Quicken Loans had a new slogan emblazoning its downtown office towers and company shuttles, and everyone I spoke with outside the city center seemed to be uttering it like a mantra: OPPORTUNITY DETROIT.

Economists fret that Detroit, in the absence of the manufacturing economy that built it, no longer has any reason to be. And indeed, large chunks of the sprawling, 139-square-mile city have literally vanished: Of Detroit’s 380,000 properties, some 114,000 have been razed, with 80,000 more considered blighted and most likely in need of demolition. But the new prospectors have an abiding faith that cities, like markets, are necessarily cyclical, and that the cycle has finally come around. It is the same ethos that turned other urban disasters into capitalist boomtowns — New Orleans after Hurricane Katrina or the cities of Western Europe after World War II. If the scale of Detroit’s failure is unprecedented, then so (the local reasoning goes) is the scale of its opportunity.

In the process, the Motor City has become the testing ground for an updated American dream: privateers finding the raw material for new enterprise in the wreckage of the Rust Belt. Whether or not they’re expecting to profit, Gilbert and other capitalists — large and small — are trying to rebuild the city, even stepping in and picking up some duties that were once handled by the public sector. Shop owners around the city are cleaning up the blighted storefronts and public spaces around them. Only 35,000 of Detroit’s 88,000 streetlights actually work, so some owners are buying and installing their own. In Gilbert’s downtown, a Rock Ventures security force patrols the city center 24 hours a day, monitoring 300 surveillance cameras from a control center. Gilbert is proposing to pay $50 million for the land beneath the county courthouse and a partly built jail near his center-city casino, with the intention of moving the municipal buildings to a far-off neighborhood; his goal is to clear the way for an entertainment district that flows south, without interruption, from the sports arenas past his casino and into downtown. Detroit’s new mayor, Mike Duggan, told me he had no problem with the private sector doing so much to shape his city: Other metropolises had their entrepreneurs and deep-pocketed magnates who built and bought and financed things.