TDY indeed did drop from $65/sh to $23/sh (even $21/sh for a few days). This happened because earnings had dropped and partly due to the overall economy. Since 2009, the price per share has risen a huge amount (from $21/sh to $76/sh), unfortunately, earnings have only risen slightly (from $3.10/sh to $4.40/sh). Indeed, this company's share price is very sensitive to its EPS (has a large multiplier effect) and very sensitive to the trend of its earnings. If we see earnings level off or drop slightly to $3.10/sh, indeed we could see the share price drop to $21/sh. It would not take much in terms of government contracts to drop TDY way down down to a price below $30/sh. Contractors are always first to go when there are cuts. There have been some government contract revenue numbers announced, but these are "potential" revenues and are unlikely to be the true amount TDY sees.
If a rise in income from $3/sh to $4/sh can send TDY up from $21/sh to $76/sh, then a slight drop in income from $4/sh to $3/sh can indeed send TDY from $76/sh to $21/sh, so proceed with caution.