So much for that weak dollar, huh? The Bitcoin craze may finally be peaking and now another "alternative" currency is plunging too: gold.

Gold, which in its defense is at least a tangible asset, sank 5% Friday and fell below $1500 an ounce. Gold has fallen out of favor lately as stocks have continued to surge. Several Wall Street banks slashed their gold price targets earlier this week.

The sell-off in gold shouldn't come as a huge surprise, although the magnitude of it is stunning. Gold often does well in times of extreme fear (not happening right now) or when investors are seeking a good inflation hedge.

And even though there are some investors who feel the Fed's quantitative easing programs will eventually spark a nasty bout of inflation, that seems well off into the future.

Related: CNNMoney's Fear and Greed index back in greed

In fact, the latest producer price index figures, released Friday, showed that wholesale prices fell 0.6% in March. That might be one of the big reasons why gold was tanking.

Traders on StockTwits had more to say about the shiny yellow metal.

The SPDR Gold Shares (GLD) and Market Vectors Gold Miners (GDX) ETFs were top trending tickers. And two levered-up gold ETFs (funds on steroids) were trending as well: The Direxion Daily Gold Miners Bull 3X Shrs (NUGT) and its companion on the downside, the Direxion Daily Gold Miners Bear 3X Shrs (DUST).

chefopopov

$GLD Wow talk about a huge margin call; that looks like straight liquidation; until that somebody is done selling things do not look rosy...

MarketOwl

Some serious liquidation going on in gold. Perhaps John Paulson is throwing in the towel. $GC_F $GLD

Ha! It's impossible to know right now just who is dumping gold. It's a plausible theory that hedge funds and other large institutions are running for the exits. There were also rumors that Cyprus might need to sell gold to raise capital. But it almost doesn't matter who the sellers are. There clearly is selling. And a lot of it.

But gold wasn't the only metal that was tanking. Silver was down 5%. And the iShares Silver Trust (SLV) was also trending on StockTwits.

Platinum and copper (which is more of an industrial as opposed to precious metal) fell too. Several traders think the sell-off in silver and gold (cue the Burl Ives ... or U2) is just beginning.

TheMarketman1

REPEAT: The metal's have lost there luster, look for violent sell off to $900 in gc_f $GLD and $17 in si_f $SLV Bearish

sspencer_smb

one thing i learned from the $SLV sell off a couple of years ago is don't bottom pick commodities. $GLD

There is a reason why gold and silver are tough investments to own. They are extremely volatile.

And like many commodities, they tend to move more on speculation as opposed to true changes in supply and demand.

Warren Buffett has often railed against gold for this reason. He notes that gold is an asset that just sits there. It doesn't produce anything in the way that a company does. He has a good point.

Related: Buffett on why stocks beat gold and bonds

That said, there were still a few brave gold bugs on StockTwits who were salivating about the opportunity to buy on the big dip.

SnoopyJC

Not good day to be a gold bug!! (Unless you can BUY!) $GLD $GC_F $GDX

Joe Cool is a gold bug? Who knew? Wonder if Woodstock (or as Baby Buzz says it, Woogenstock) is also long the yellow metal.

JuanLobato

$GLD Panic will pass and the big players will buy cheap gold. Long at 1512 Bullish

It definitely looks like a panic. I personally don't think gold is doomed just yet. It may make sense as a teeny part of your portfolio -- especially if you're worried about the upcoming debt ceiling battle in Washington. Or Europe imploding again. Or North Korea. Or a bond sell-off and spike in interest rates. You catch my drift. Gold can be a good hedge. Just don't go overboard.

Bitcoin speculators, including twin brothers who are fond of rowing but don't "like" Mark Zuckerberg, have learned the hard way that what goes up must come down.

And speaking of Bitcoin (what are the Winklevii thinking?) there were tons of great tweets from followers this week that were worthy of Reader Comment of the Week. But one from Friday is my clear favorite ... especially since it reminded me of fun times as a video-game loving teen in the late 80s.

https://twitter.com/MattAndrewsRVA/status/322701795224850432

Hilarious. I hope Link wasn't long Bitcoin. Speaking of fictional currencies, here was my take on the "value" of Bitcoins.

Glad my cash is not in Bitcoin-denominated account. Had foresight to exchange them for galleons, sickles & knuts! #harrypotter TGI Almost F! — Paul R. La Monica (@LaMonicaBuzz) April 11, 2013

Enjoy the weekend, everyone. Have fun spending your hard-earned legal tender paper currency!