I'm been on HRT for several months and had nice development in my breasts. They now bounce/jiggle when walking. As others have posted, they brush up against my arms whe I try and do certain tasks.  It is nice now to wear bras for security. A sports bra is a requirement now when I run.

Mine are still too small to bounce significantly when I walk.  But going down stairs, I tend to trot, and they sure bounce then! 

I had to start wearing sports bras by 6 weeks on HRT to prevent nipple pain when I walked.  Now I wear a padded bra for vanity.  The padding brings me up to about an A.

It's awesome when the girls start acting properly!

Breast bounce definitely lets you know that the girls have arrived. But really, this is just one more aspect of gender confirmation.

yay bounce!  It was wonderful when I realized my boobs were jiggling when i walked and i needed to get a bra.  Congrats!

I agree it is a nice aspect of gender confirmation