iStockphoto A mere quarter percentage point rate increase by the Federal Reserve might seem small and gradual, but for millions of consumers with credit-card debt it will be stinging. In a report this week, WalletHub analyzed data and found that U.S. consumers have been piling on credit-card debt at an alarming pace, adding $92 billion in new debt last year alone—twice the postrecession average. Lenders so far seem only too happy to extend credit, thanks to low levels of defaults and...

Getty Images Early investors in LongFin Corp, which began trading last week on Nasdaq, were in for a big windfall as the stock surged after buying blockchain technology provider Ziddu.com. It was a wild ride, however. By noon on Monday, the stock skyrocketed to a high of $142.82, but since retreated to close at $72.38, which still marked a gain of 229% and values the company at more than $4 billion. Last week, its market capitalization was around $265 million. It’s unclear whether such mania,...

The No. 1 and No. 2 digital currencies, bitcoin and Ether tokens, on Friday are on track to wrap up a volatile September—marked by blistering criticism from high-profile executives and intensifying regulatory focus—in the red after trading little changed on the day. Where are bitcoin and Ether trading? Price of a single bitcoin BTCUSD, -0.34% was nearly unchanged at $4,199 on Friday. Over the past week, bitcoin rose by about 20%, but it’s still on track to end September 16% lower. Over the...