BiggerPockets

BiggerPockets is a real estate investing community, podcast and publisher. Wikipedia credits it with coining the BRRRR acronym, and it published the book that laid the strategy out as a repeatable process. Much of the vocabulary BRRRR investors use, from the 70% rule to the infinite return, spread through its forums.

The strategy predates the name. Investors have bought, improved and refinanced rentals for as long as cash-out refinancing has existed. What BiggerPockets added was a checklist, a large audience trading deal numbers, and a set of rules of thumb that made the method teachable.

Rules of thumb are where to be careful. The 70% rule and the infinite return were calibrated in a market with 4% mortgage rates and cheap distressed inventory. At 7% rates the refinance still returns the cash if the purchase was right, but the rental afterward is thinner than the examples from a decade ago. The method holds; the numbers have to be run fresh.

Further reading: BiggerPockets on Wikipedia.