SAN FRANCISCO — The last few months have not been good for Bitcoin. The value of the digital tokens has steadily dropped. Bitcoin trading on cryptocurrency exchanges has slowed. And using Bitcoin to buy legal items? That has also dropped.

But one corner of the Bitcoin economy is still going strong: the sale of illegal drugs and other types of lawbreaking.

The amount of cryptocurrency spent on so-called dark net markets, where stolen credit card information and a wide array of illegal drugs can be purchased with Bitcoin, rose 60 percent to reach a new high of $601 million in the last three months of 2019, according to data released Tuesday by Chainalysis, a firm that tracks every Bitcoin transaction and serves as an adviser to an array of government authorities.

The continuing growth of illegal transactions underscores the difficulties that Bitcoin has had in moving past its reputation as a refuge for scoundrels, even as Wall Street institutions have begun buying and selling the digital tokens.