Emily: I noticed you have a fascination with Greek letters. The plates on your car, No Delta, your cuff-links are the Greek symbol Pi. I am intrigued.
Nitro: (extremely pleased with her curiosity. Emily smiles at seeing nitros passion for whatever she has unearthed. Nitro thinks, how can I explain this - we are already on our fourth shot of Stoli and three glasses of wine, and I don't want to put her to sleep. Ah whatever, she is sharp as a tack, here goes nothing. Emily pours more wine into nitros glass. nitro thinks she is not driving his car no matter how drunk she gets him.)
You see, my profession is, I am a stock options trader. Actually, I trade the world markets around the clock. But when I am trading options, a pure option trader is not so much interested in the direction that a stock goes, more on how much the stock moves in either direction, so we make bets on this unidirectional volatility ,whether we think it is too high or too low. Delta is the quantity of an option that describes how exposed an options trader position is to this directional underlying stock movement. We don't like that exposure and try to fight it as much as possible, hence my No Delta plates.
(Emily listens intently, takes it all in. Her penetrating blue eyes didn't blink once during the explanation)
Nitro: If I may defer on my fascination with Pi to when I am more sober...