On "Halftime Report," Legere said he was pleased with T-Mobile's competitiveness.
"AT&T and Verizon are offering various forms of trickery to lock their base in because they don't know what to do," he said. "What I like more than anything is after two years that I've been doing this, the common question is, 'Hey, they're so much bigger. What are you going to do when they beat you up?' This is it, kids.
"We're porting on a post-paid basis about 2.2 and 2.3 to one every day, which means every day 2.2 customers come to us from them and one goes out the door. So, we can compete. They're not used to competing."
On Tuesday, the Federal Trade Commission sued AT&T on for deceptive and unfair "data throttling."
Read MoreFTC sues AT&T for 'deceptive' and 'unfair' data throttling
Legere claimed the nation's fourth-largest wireless service provider had "more spectrum per POP than anybody," or point of presence, and added that T-Mobile would be rolling out a new 700MHz band.
The outspoken CEO also said the company had new developments in the works but declined to elaborate.
"It's so big that if I told you right now, we'd fall off the stage," he said.