air pocket

What does "air pocket" mean here? Difference?
“The one stock that could kind of surface as strong here is Netflix,” he said on CNBC’s “Trading Nation.” “You’re definitely seeing a little bit of relative strength. There’s a pretty good air pocket right there between FANG and Netflix.”

Source: FANG is 'dead money'—with one exception, technical analyst says

If you are trapped underwater or in a flooded cave, if you find an air pocket (a volume of air trapped by something impermeable above), then you can use this to breathe, and stay alive. It seems rather an odd choice of metaphor here; an air pocket enables you to stay alive, but not do much else, and you probably won't even stay alive for more than a few days.