"Even Apple can't affect this market rally," said Yu-Dee Chang, chief trader at ACE Investment Strategists. "We're at the psychological 1,500 level so we may spend some time—maybe even days—going back and forth around here. And if we don't fall off, the market has another leg up."
Chang noted that since the market lows of March 2009, the index on average has cycled between gains of 13.5 percent and declines of 7.7 percent.
"So take the low in November—a 13 percent gain would put us near 1,520 on the S&P," explained Chang. "And then people will look for reasons to pull back. And when we get to that level, we would want to be a little bit cautious."
Among earnings, Apple plunged more than 12 percent after the world's most valuable company by market cap posted revenue that fell short of estimates and iPhone sales that missed quarterly expectations. The tech giant's stock has plunged nearly 33 percent from its all-time high of $705 last September. At least 13 brokerages slashed their price target on the company. (Read More: Apple Earnings Hit Could Whack Tech Hard)
Major Apple suppliers including Broadcom, Skyworks and Qualcomm also declined. (Read More: Apple Suppliers Slammed, but Experts Say Buy)
Meanwhile, Netflix skyrocketed more than 40 percent after the movie-streaming site posted a profit of 13 cents a share, blowing past expectations for a loss. In addition, the company handed in current-quarter guidance that topped estimates.
On the economic front, weekly jobless claims fell 5,000 to a seasonally adjusted 330,000, dropping to its lowest level in nearly five years, according to the Labor Department . Analysts polled by Reuters had expected claims to rise to 355,000 last week.