A 52-week low is the lowest price at which a share or other security has traded over the previous 52 weeks. It is published alongside the 52-week high in price tables and on watchlists, and both are explained in full on the 52-Week High and Low page.
Some investors look for shares near their 52-week low as possible bargains, while others treat a new low as a warning sign; a short rebound after such a fall can be a dead cat bounce.