Wasn't it in Operator where the tipster was shocked when the tippee shorted two large lots of the targeted security? And when both went off short without a hickup, he bought them back, and went long a multiple of that initial position?
A large trader (the tipeee in your parlance) sold two lots of 10,000 shares each to see how the market absorbed both lots. Following the second sale he was convinced there was a commited buyer out there and covered the 20,000 share short and bought an additional 10,000 holding 500 shares at the average price the 10,000 shares cost him for the tipster. The way the market absorbed the second lot convinced him the game was on and being long was the place to be.
Are u going to try this with ES? Sell 10,000 lots and see if they go quick, if so sell another 10,000 to make sure there's a bull market?
He was not trying to ascertain if it was a bull market he was making sure there was a relentless buyer of a particular stock.