The stock is (highly likely) in consolidation phase...
Indeed, given p/v/t-distributions:
~0.8 M shares were bought (Sep 12) in range 148-150
~1.2 M shares were bought (Sep 12) in range 150-152
~1.6 M 'spec. shares' were sold (Sep 13) in range 154-157 (av. ~155.8)
Thus, i) balance is positive, though very low ~0.4 M (=0.8+1.2-1.6), indicating dominant role of short-term st-strategies, ii) small number of 'new mt/lt-investors' (mt-trend followers) stepped in, and iii) 2-days (Sep 12-13) spec. st-trading provided up to ~3.7% fast return.
As you know, after consolidation the stock usually continues former trend.
Don't also forget that 'price-volume' correlations are negative (the higher price --> the lower volume, and otherwise).
PS. Just small number of shares (~0.25 M) were bought in range 152-154 (Sep 13)
Good luck.