NEW YORK (TheStreet) -- Bitcoins haven't received that much public attention lately, but investors would be wise to keep their eyes on the digital currency, because it could stage another big rally.

Yes, it's been more than a year since the collapse of major bitcoin exchange Mt. Gox, and bitcoins aren't the fad they were in 2013. But the waning public interest is allowing a technical pattern to form that often follows investment manias that have blown up.

Bitcoins have already gone through a couple of parabolic rallies. Within the span of a few months from late 2012 to early 2013, they exploded parabolically in price  from the single digits to as high as $250, before crashing back down to the $40s (according to prices at the Bitstamp exchange). Here's a chart since Jan. 1, 2013 showing these moves.

From the initial crash low in the $40s in April 2013, bitcoins formed a sideways-to-down contracting pattern. It took until November 2013 for the digital currency to break out of that pattern and make higher highs than the previous peak in the $250s.

The same week that happened, prices reached the $360s. That five-week rise created a rally that was even more parabolic than the first one, and it was only in its infancy! By the time the bubble popped around Thanksgiving 2013, bitcoins had risen into the $1,160s. This $1,077 rise took about two months from the September 2013 low, and about seven and a half months from the initial crash bottom of the first parabolic rise. Mania? Maybe.

Parabolic rises in all asset classes end with prices returning to the origin of the parabolic pattern or going even lower. History is full of examples going back to the tulip bulb mania of the 17th century.

The first parabolic rise of bitcoins returned to the origin of its parabola -- in that case, in the $40s. Earlier this year, the second parabolic rise returned to the origin of its parabola, which was the zone between the April 2013 high and the September 2013 low.

So is the next bitcoin parabolic rise about to begin? It appears so, but the digital currency must surpass $990 to confirm this.

In the meantime, breakouts above the March reversal point of $300 will hint that the lows of the contracting pattern off the parabolic highs of late 2013 are in place. Breaking above the November 2014 reversal point of $449 will increase the odds, as well. Then, only the March 2014 reversal high near $700 will stand in the way of a run on $990 and even higher prices.

If the rest of the Decision Support Engine sets up perfectly, then the recommended action will be to buy, buy, buy!

Until either $300 is broken or the Decision Support Engine signals a trade, investors could begin accumulating a position following a break of January's low near $153 and then buy aggressively into any test of $100, plus or minus $10. This is the September 2013 low, where the second parabolic rise started.

Don't let the recent silence take your eyes off this asset, as it could prove to be one of the greatest wealth-building opportunities of the next few years.

This article is commentary by an independent contributor. At the time of publication, the author held a small position in bitcoins.