This chart shows why the S&P could surge 12 percent from here

Investors better gear up for another big leg up in the market. A 12 percent surge, to be exact.

That's what the chart of the S&P 500 is telling Evercore ISI technician Rich Ross. As the S&P 500 made another intraday all-time high on Thursday, Ross said the new high is actually a breakout from the S&P's trading range over the last few months.

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The previous trading range had been bounded from 2,330 on the lower end to 2,400 at the higher end, according to Ross, and he takes that same range to establish a new record high in the shorter term for the S&P.

"What we like to do is we take the height of this pattern, 2,330 to 2,400, and then we project that out," he said Thursday on CNBC's "Trading Nation." "That's 70 index points from 2,400, and that brings us up to that 2,470 target."

So in the shorter term, Ross said, expect the market to move up another 2 percent.

But the real story is how high Ross sees the S&P moving in the longer-term. To establish that level, the technician looks at the index from the end of October 2016 to the height of the S&P's most recent trading range, the 2,400 level. Ross essentially creates a "bullish flag formation" with the bottom of the flag beginning at 2,100, where the S&P sat in October. He doesn't believe the market has reached the top of the flag.

"The flag flies at half mast, halfway within the pattern," he explained. "We can project out another 300 points from that 2,400 over time and that brings us to our 2,700 upside target on the S&P."

In short, according to Ross, the S&P 500 still has another 12 percent upside to go.

Looking more closely at the charts on Thursday, Ross concluded that "the breakout today gets us to 2,470 in the short- to intermediate-term, and over time we can get to 2,700 on the S&P 500."

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Trading Nation is a multimedia financial news program that shows investors and traders how to use the news of the day to their advantage. This is where experts from across the financial world – including macro strategists, technical analysts, stock-pickers, and traders who specialize in options, currencies, and fixed income – come together to find the best ways to capitalize on recent developments in the market. Trading Nation: Where headlines become opportunities.

Michael Santoli

Michael Santoli joined CNBC in October 2015 as a Senior Markets Commentator, based at the network's Global Headquarters in Englewood Cliffs, N.J.  Santoli brings his extensive markets expertise to CNBC's Business Day programming, with a regular appearance on CNBC's “Closing Bell (M-F, 3PM-5PM ET).   In addition, he contributes to CNBCand CNBC PRO, writing regular articles and creating original digital videos.

Previously, Santoli was a Senior Columnist at Yahoo Finance, where he wrote analysis and commentary on the stock market, corporate news and the economy. He also appeared on Yahoo Finance video programs, where he offered insights on the most important business stories of the day, and was a regular contributor to CNBC and other networks.

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