AH can always have dramatic shifts in pps on low volume. I do not believe it will have an impact on Mondays trading. This is what Nasdaq has to say about After Hours, and its volatility:
Investors may trade in the Pre-Market (4:00-9:30 a.m. ET) and the After Hours Market (4:00-8:00 p.m. ET). Participation from Market Makers and ECNs is strictly voluntary and as a result, these sessions may offer less liquidity and inferior prices. Stock prices may also move more quickly in this environment. Investors who anticipate trading during these times are strongly advised to use limit orders.
You can check out the AH trades here: http://www.nasdaq.com/symbol/rad/after-hours#.UQ02j2fLpGY
Note the large volume trades at 1.70 and 1.71. Some smaller trades towards the end brought to 1.66. Take here is big volume after hours (good) and big trades at 1.70 and 1.71 (also good). We're talking multiple buys at 40K share range at 1.71.
After hours volume was 777K. of that volume, about 10 big trades = 700K shares traded at 1.71 to 1.72. Basically, 90% of AH trading was in the 1.70 range.
The AH question is: who bought those big blocks of RAD stock in AH to the tune of 700K shares? Inquiring minds want to know.