Other drivers behind the rally were the strong dollar, resumption of giant takeovers, new home sales soaring and the return of red-hot biotechs.
The most important signal, though, was the strength of technology stocks.
"We have a magnificent tech rally going here, one that we have to talk about because I think it is the real deal and tech is such a huge part of the S&P 500," Cramer said.
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The run in tech began when Salesforce.com reported a fantastic quarter last week, which proved that the cloud is still soaring. The next day, Cisco Systems reported a strong quarter when few money managers were expecting one.
On Friday, semiconductor equipment maker Applied Materials confirmed strength in the microchip business. On its conference call, management confirmed that semiconductor orders for chips have risen, particularly in the flash chips used for cloud storage.
"Applied Materials matters because it doesn't get a lot of orders unless there is real demand for the massive number of devices that semiconductors go into," Cramer explained.
The tech rally was further ignited when analysts predicted that Western Digital will say good things when it updates its guidance on Thursday, which is could be good news for the beleaguered disk-drive makers.
On Tuesday Cowen also upgraded Microsoft, which Cramer regarded as being incredibly important for technology because Microsoft was the major driver of the decline one month ago. Cowen noted that its transition to the cloud is back on track, which could be big for tech.
"The leader right now is tech, and when tech is at the vanguard, the market can give you a powerful and lasting move higher," Cramer said.