26,200,000.  That's A Lot Of Burgers

That big number is how many shares insiders have filed to sell in the open market.  Most probably the reason shares of Shake Shack are down almost 6% today.
Perhaps another reason are the above photos. The top one is a Shake Shack burger priced at $5.19;  the other is an In N Out burger costing $2.35.