In 2016, chip-maker Nvidia was the hottest stock in the S&P 500 – and it had the highest short interest among S&P 500 stocks with market capitalizations of more than $50 billion.

The semiconductor company has long been a target of short sellers, but the persistence of their bets in the face of a stock moving so forcefully against them stands out. There was about $1.5 billion of short interest at the start of last year, and it climbed steadily to $7.1 billion in mid-December. That type of behavior is “extremely rare,” according to S3 Partners, a financial analytics firm. For the record, short interest declined by about $1 billion between mid-December and the end of the year - and, as 2017 kicks off, it seems that some of the holdout shorts are throwing in the towel.

All told, it’s roughly estimated that Nvidia short sellers lost about $4.4 billion last year, according to S3 Partners. The shorts made back about $131 million last week, with the stock falling 4.7% in the first 3 days of 2017, but that’s little solace after such big losses last year. Plus, the stock is up another 3.9% in early going today, 1/9.