The “bubbles” in the wildly popular bubble — or boba — teas are becoming harder to get. What’s causing the shortage? Much like computer chips and Heinz ketchup packets, it’s a supply chain issue that’s affecting the arrival of the tapioca from Taiwan. According to the U.S. Boba Co., 99% of boba comes from overseas. Business Insider talked to Oliver Yoon, the vice president of sales and global marketing for Boba Direct, a Chicago-based supplier of bubble tea products. He said the shortage is likely to last through the rest of April. It's unclear whether boba supplies will be restored by April 30 — National Bubble Tea Day.