COMMONNAME, MM's trying to hold on to their shares. Look at the line up on L2 and notice the slightly wider spread between the current top five MM's (on the bid).
B vs. A:
SCHB .505 X .55 GVRC .50 X .555 WEIN .49 X .53 VIEW .49 X .55 PERT .49 X .62
4.5 to 6.5 cent spread. Eager to buy at .49 but don't want to give any shares up.