GrubHub made a small top formation in September/October and has been correcting lower since late October. We don't have a lot of price history to work with on GRUB, but we can still come up with a strategy.
In this one-year daily chart of GRUB, above, we can see a strong advance from late January until late September. A bullish golden cross kicked in at the end of May, and while GRUB has recently broken the 50-day average, it remains above the rising 200-day line. Volume spikes had been associated with rallies for much of the year, but two volume surges in October and November are linked to declines. Heavy volume on a price decline is the market's way of telling you that sellers want out and they are going quickly. The On-Balance-Volume (OBV) line did not move up from January through May, but the advance from May confirms the rally. Since late October, the OBV line has been weakening.
Before we look at the weekly chart, we need to point out a bearish divergence in August through September where prices made higher highs but the momentum study made lower highs. This divergence foreshadowed the recent price decline. As prices have made lower lows in November, the momentum study has not diverged and suggests that prices can move lower.
In this limited weekly chart of GRUB, above, we can see prices are above the rising 40-week average. The weekly OBV line turned up early in 2016 and has only recently pulled back. The weekly Moving Average Convergence Divergence (MACD) oscillator crossed to a liquidate-longs sell signal last month.
Strategy: It looks like GRUB can pull back further and a test of the rising 200-day moving average line could happen in the next few weeks. If GRUB holds the $32 level, it is great, and if it doesn't, we could see further weakness to around the $26 area.