Gold's "poor cousin" has jumped more than 150% in less than a year. That looks like rampant speculation, not healthy growth, and reckoning will come fast and hard, writes editor-at-large Howard R. Gold.

I was just starting to work on a column about silver mania Tuesday morning, when a big, beautifully produced ad insert—on silver, of all things—arrived with my Financial Times.

Proclaiming that "silver is the single greatest profit opportunity of our time," the insert featured a huge, nearly three-dimensional replica of a one-ounce US silver eagle, with Liberty herself reaching out her hand and In God We Trust right there for all to see.

The coin replica, some 3 1/2 inches in diameter, shone like a harvest moon, glittering with the possibility of instant riches.

And—you just can't make this stuff up—it came just a day after silver prices hit their highest level in three decades.

On Monday, silver closed near $50 an ounce, just below where it stood when the Hunt brothers tried to corner the market back in 1980 (although it's way below that record when prices are adjusted for inflation). Silver briefly set a new high Thursday.

Of course it was a coincidence—the ad, by a Minneapolis coin dealer, was three months in the making, I was told—but it perfectly captured the moment when silver moved into the full-fledged mania stage.

The Fever Spreads
It's happened with lightning speed. Last summer, before the most recent market rally began after Federal Reserve chairman Ben Bernanke announced a new round of quantitative easing (QE2), silver was still gold's poor cousin, trading below $20 an ounce.

Since then, it has rocketed more than 150%, and soared 50% in 2011 alone. Gold, meanwhile, has plodded along with the stodgy old S&P 500 index this year—though it's up nicely from last year's lows, too.

In recent weeks, silver fever has reached, well, fever pitch. Silver prices have shot up nearly 20% in April alone, as retail investors piled into the markets and the pros moved en masse into the futures and options pits.

Trading volume of silver futures at CME Group (Nasdaq: CME) hit an amazing 319,205 contracts Monday-more than 50% higher than its previous record last November. And this month, the contract's average daily volume has tripled from last year, The Wall Street Journal reported.

Both individual and professional investors have gone gaga for silver exchange-traded funds. On Monday, iShares Silver Trust (NYSEArca: SLV) saw three times the volume of the SPDR S&P 500 (NYSEArca: SPY) ETF, one of the market's biggest, and SLV's trading volume was five times its daily average in the first quarter.

And just to show how zany things have gotten, day traders have been piling big time into the ProShares UltraShort Silver (NYSEArca: ZSL) ETF, which makes doubly leveraged bets against silver prices.

How dumb is that? Well, on Wednesday afternoon, silver prices soared 7% after Federal Reserve chairman Ben Bernanke told his first live press conference that he doesn't expect to raise interest rates soon, and that he'd like to see a little more inflation than the official figures are measuring now.

The ultrashort silver ETF plummeted 12% on that day.

One seasoned trader told The Journal that day traders "are going crazy."

"It's typical of the bubbly speculation that's been going on in silver," he added.

NEXT: Imminent Correction?

Tickers Mentioned: Tickers: ZSL, SLV