The pool of homebuyers has dropped to a record low, meaning that sellers are in a worse position than buyers in the current market, according to new data from Redfin. 

There were an estimated 51.3% more home sellers than buyers in the U.S. housing market in July, which was down from 51.8% in December and up from 47.9% the month before. 

The number of buyers in the market fell to a record low of 967,000 — nearly half a million fewer than the 1,463,000 million buyers. 

Nearly 80% of major cities in the U.S. are now buyer's markets. Miami has the highest ratio, with 154% more sellers than buyers. Miami is followed by Houston (130%), San Antonio (116%) and Austin (112%). 

Redfin defines a market where there are over 10% more sellers than buyers as a "buyer's market," and the market is considered balanced when the ratio between buyers and sellers is less than 10%. 

"When sellers outnumber buyers, buyers typically have more negotiating power because they have options," Redfin data journalist Dana Anderson wrote.