$AAPL last traded above $600 on November 1st, 2012, when the stock hit $603 in intraday trading. It last closed above that mark on October 26th, 2012, when it ended the day at $604 per share.
Five Year Chart for $AAPL
Source: Yahoo! Finance
Those levels were on the downward slope of sharp decline that began just a few weeks before, as shown in the chart above. $AAPL hit a closing high of $702.10 on September 19th, 2012, and sank to a multiyear low of $390.53 one year later on September 19th, of 2013.
Apple's stock has been on a tear since the company announced results for the March quarter of 2014 on April 23rd. In addition to higher-than-expected iPhone sales, Apple announced an increased dividend and share buyback program, as well as a 1-to-7 stock split that will take place in June.
At Monday's closing price of $600.96, each share become seven shares trading at $85.85..
Monday's gains were steady, with the stock gaining in the opening hour of trading and staying in positive territory for the rest of the day. All told, $AAPL has gained $76.21 per share since April 23rd's closing price of $524.75, a gain of some 13.7 percent.
Monday's $AAPL Chart
Source: Yahoo! Finance
*In the interest of full disclosure, the author holds a tiny, almost insignificant share in AAPL stock that was not an influence in the creation of this article.