After months of churning in a narrow range, the markets could be in store for a very sharp move, according to veteran technician Ralph Acampora.

"I think if you look at the S&P 500 and put a Bollinger Band on it, it's getting very tight," Acampora told CNBC's "Futures Now" on Tuesday. Technicians often look at Bollinger Bands as a measure of volatility in the market — they tend to tighten during periods of low volatility and widen during periods of heightened volatility. The S&P 500 has not seen a 1 percent move in either direction since July 8 — its longest such streak since 2014.

"It's like winding a spring," he added. "This tells me that the move should be pretty dramatic either up or down, and I opt for the up because of the current leadership in technology and financials."

Technology and financials are the two best performing sectors over the last three months, rising a respective 9 and 4 percent while the S&P 500 is up 3 percent in the same period.

But what makes Acampora even more bullish lies beneath the surface.

"What's really impressive — and I've been looking at charts for 50 years and I've never seen [anything like this] — when the S&P 500 and moved to new all-time highs, it was led by market breadth," said the director of technical analysis for Altaira Capital Partners. "That means the majority of stocks were stronger than the large blue chip averages. I don't think I've ever seen anything like that."

Acampora explained that the outperformance of small and mid-cap stocks lead him to believe that the market is broadening, and that could mean even more new highs in the near future.

"I'm fairly bullish longer term," he added.