The Spanish bolsa has two common definitions — both with noteworthy and related etymologies.
Bolsa commonly means “purse.” And indeed, both come from the same root: the Greek byrsa, meaning “hide, leather.”
We can see the connection if we remember that the ‑b- and ‑p- sounds are often interchangeable, as are the ‑r- and ‑l- sounds. Thus the b‑l-s of bolsa maps to the p‑r-s of purse.
Similarly, bolsa has a second definition in Spanish: the “stock market.” It makes sense if we think about the bolsa and the purse as, the places where money is kept. And in English, a less-common synonym for stock market is bourse — and we see this same word in French all the time, the Bourse de Paris. With bourse, only the ‑p- and ‑b- are interchanged, not the ‑r- and ‑l-, thus mapping the b‑l-s to b‑r-s.