This post is one in a series on prominent company nicknames. See all 25, and share your thoughts and memories about Mr. Softee below in the comments.

You would be hard-pressed to find a professional stock trader today who didn't know that "Mister Softee" is Microsoft (NYSE: MSFT) . The nickname is so widely-used among investors that it seems to barely need explanation. But there is actually a quite simple reason for the derivation of the moniker. Here is how I imagine it taking hold:

Once upon a time in a land known as Manhattan, some Wall Street traders were enjoying some after-work beers. After about the fifth brew, these professionals began to gain insights, as they so often do today, into weighty topics.

They pondered the amorous tastes of Ginger and Mary Ann from Gilligan's Island. They debated whether "Freebird" or "Stairway to Heaven" was the greatest rock song of all time. Then, one of the traders had the burst of insight that the ticker symbol for Microsoft ("MSFT") has some of the same letters as beloved self-serve ice cream Mister Softee. And so, one of the most ubiquitous bits of Wall Street slang was born.