Yes i've day-traded both of these equities at times, almost exclusively
One is common (PBR) one is perferred (pbr.a)
Pbr- Is slightly higher priced (28.27 todays close)
Pbr.a- Is slightly lower priced (25.96 todays)
Pbr [common] is more liquid and has a bigger intraday range
Pbr.a is a little less liquid and has smaller intraday range
Both trade pretty much together as far a Net change on the day.
Both trade nice volume and have about 1k-5k shares available on both the bid and ask throughout the day, to trade