Ask most people about the bitcoin bubble, and they’ll probably have the same reaction: It’s interesting, but it won’t affect me. After all, they’ll figure, they aren’t investing in bitcoin, so if there is a bubble, and it does burst, they’ll be just fine.

Well, maybe they should start worrying.

The market for cryptocurrencies—digital tokens used to transfer money between individuals’ computers with minimal fees—has grown in stature in recent years and is increasingly entwined with broader financial markets as well, a trend that is likely to continue. Bitcoin is now traded by some of the institutional investors around which bond and stock markets revolve. The Wall Street Journal has reported that Goldman Sachs Group Inc. is considering opening bitcoin-trading operations. Cryptocurrencies also are being used to raise capital by more companies.

As the bubble grows, analysts say, a crash has a greater chance of affecting investor sentiment about stocks, especially in the technology and financial sectors.

“Any product that blows up, there’s always collateral damage,” says Joe Kinahan, chief market strategist at brokerage TD Ameritrade . Tech and financial “companies who are relying on it for business, and those who have put a significant investment into the [blockchain] infrastructure would be the first” to suffer collateral damage, Mr. Kinahan says.