No, I am pretty sure its mass is exactly equal, just the charge is opposite:
https://en.wikipedia.org/wiki/Electron
https://en.wikipedia.org/wiki/Positron
https://en.wikipedia.org/wiki/Proton
https://en.wikipedia.org/wiki/Antiproton
it is more of a theoretical explanation of why there is so much matter
https://en.wikipedia.org/wiki/Baryon_asymmetry