We 7th graders didn't know which company to buy and our teacher told us we had 1 minute left to choose a stock. We looked around the room and I saw the calculator in front of us. "Oh great, let's go with Texas Instruments, TI, everyone has one of their calculators!"...So, we bought $10,000 of "TI", which turned out to be "Telecom Italia", an Italian phone company...
...which actually did REALLY well, we were nationally ranked in the game after a couple of weeks, but TI ended up tanking for whatever reason and we lost in the end.