By Anthony Mirhaydari

MSN Money

It’s no secret: We’ve just been through an economic nightmare.

But that’s old news. And many, including value investor and hedge fund operator Bill Ackman of Pershing Square Capital, who made billions shorting housing-related bond insurer MBIA (MBI, news, msgs) in the last days of the boom, are now calling for its resurrection.

In a leaked research report titled “How To Make A Fortune,” Ackman doesn’t just say the path to wealth through homeownership has been restored. He says this road has seldom been easier.

Why it’s time to buy

Basically, the bull’s case as outlined by Ackman can be boiled down to a few simple bullet points:

• Home prices are at their lowest valuation in at least a generation.

• A large number of forced sellers gives buyers negotiating power.

• Attractive, low-rate financing.

• Still favorable long-term supply dynamics as the U.S. has one of the best demographic outlooks in the developed world.

• Housing is an out-of-consensus idea that is under-owned by institutional investors.

The most important factor is affordability.

With home prices down by nearly one-third from their high, housing affordability as calculated by the National Association of Realtors has moved to the highest levels since the recordkeeping started in 1971.