This paper investigates how auction bidding formats affect U.S. mortgage foreclosure sales. Exploiting a staggered adoption of electronic bidding across<br>adjoined counties in a “stacked” difference-in-differences design, I show that foreclosure auction success increases by 27%, and price discounts contract by<br>42%. The effects are stronger in areas with more remote courthouses, and for properties in better conditions. Buyer composition of electronic foreclosure<br>auctions shifts towards local non-professionals, who are less likely to buy-to-let and flip acquired properties ex-post. This evidence suggests that technological<br>modernizations in real estate markets can lead to better matching, deepen liquidity and foster financial inclusion.