Track High Price of Stock from Date of Purchase

I am a relative newcomer to the world of Excel but know enough to get around.

I am trying to figure out the cleanest way to track the high-water mark of the price of a stock I own ONLY AFTER my date of purchase.

Each day I log on, a VLookup pulls up the recent stock price. How can I create a formula that will store this price and compare it to the stock price the next time I log in and save the highest of the two prices for the next day's comparison.

Day 1 $10
Day 2 $11- The $10 is replaced by $11
Day 3 $10- The $11 is retained.
Day 4 $12- The $11 is replaced by $12.

Any assistance would be greatly appreciated!!

Thanks! This seems to work well!