That's the Joe Jennedy shoe shine boy principle from 1929, that I've already referred to. It worked for Joe (if it is a genuine event).... it seems to me that when waitresses are talking about it, it's a clear sell.
Joe Kennedy decided to stop to have his shoes shined before he started his day's work at the office. When the boy finished, he offered Kennedy a stock tip: "Buy Hindenburg." Kennedy soon sold off his stocks, thinking:
"You know it's time to sell when shoeshine boys give you stock tips. This bull market is over."
"You know it's time to sell when shoeshine boys give you stock tips. This bull market is over."
