Matt Levine's latest Money Stuff column does a good job explaining why a lot of smart people are trying to figure out a market-making model for homes (see companies such as Opendoor):

People want to apply the market-making model to homes. This makes sense. Buying or selling a home is a long slow uncertain annoying process. The value of immediacy is high, especially for a seller. If you decide to sell your house and go to a website and spend 10 minutes filling out a form and then someone wires you cash for the value of your house, that is much much much better than hiring a broker and listing the house and holding open houses and so forth. You’d be willing to pay a market maker a lot for that immediacy. (By selling your house to the market maker at a discount.) And if the market maker is good at acquiring houses, then it will have a lot of inventory, which will make it a good seller of houses. If you want to buy a house, you will naturally go to the market maker’s website, because it’s where the houses are.

Levine also explains why a market-making model is that much more difficult for homes compared to things like stocks. In a slowing/slumping housing market, it's pretty easy to lose money as a market maker. (That is, unless you can somehow accurately predict that a slump is coming.)

Last month, Opendoor lost money on 42% of its home transactions. This is a result of them buying homes from people when prices were X and then selling these homes many months later when prices were less than X.

However, I'm not so sure that this has to be an existential problem. Opendoor's primary value proposition is instant liquidity for homeowners. And this value proposition is at its strongest when the market is in fact slumping. Because the alternative -- selling with a broker -- is less attractive.

So the current environment may eventually turn out to be a boon for Opendoor. Of course, we won't know for a number of months.

Full disclosure: I am long $OPEN. And yes, it is painful right now.

Matt Levine's latest column is a good follow-up to yesterday's post about Zillow exiting the algorithmic home-buying business. In it, he talks about the differences between being a market maker and being a trader of homes. Part of his argument is that if you're a pure market maker then, in theory, you don't really care about where home values are going. Because either way, you're just earning a spread.

Here's an excerpt:

A market maker is someone who buys and sells an asset in order to profit from the spread, not someone who accurately forecasts the price of an asset six months from now. End users want to buy or sell stocks or bonds or houses, they want to do it quickly at a predictable price, so they go to a market maker who will provide that service. The market maker buys from sellers and sells from buyers and does its best to match them up; ideally it buys an asset from a seller and resells it to a buyer within a fairly short time. It collects a “spread” from the buyer and seller: It buys from the buyer at a bit less than the fair market price, and sells to the seller at a bit more than the fair market price, because it is providing them a valuable service, the service of “immediacy” or “liquidity,” the service of always being available to buy or sell. 

The problem with real estate is that you're not able to buy and sell with the same kind of rapidity:

But in the house business you can’t generally buy a house in the morning and sell it in the afternoon. You sign a contract to buy a house in the morning, then you do an inspection and title search and stuff, then a few weeks later you close on the house and deliver the money, then you spruce up the house a bit, then you wait for a buyer to come in — which takes, not seconds as it does in the stock market, but days or weeks or months — then you show the house to the buyer, then you sign a contract to sell it, then they do an inspection and title search and stuff, then you wait around for them to get a mortgage, then a few months later you close on the sale.

This is an important distinction. And so he argues that what we're actually talking about is the business of trading homes, which means that you have to have a view (and hopefully some conviction) on where home prices are going to go in the future. Sometimes you will be wrong. But that's okay, as long as you're right more often than you're wrong.