2nd Wave?

Just a quick question... I have sent out all my secondaries and have just been patiently waiting (to the best of my ability). But i have yet to be notified of rejection (thankfully) or interview. I know I applied a bit late, am I to take this silence that I am in the 2nd wave (if there is such a thing). And if so, can someone clarify what 2nd wave actually is... i would think that I will be offered and interview if all you others that already have decide to go to different schools (or something along those lines). I really hope there is a 2nd wave because i'm slowly but surely losing hope...