Many short sellers of Weight Watchers no doubt felt too down to look in the mirror this week after company stock unexpectedly ballooned nearly 170 percent.

You can thank (or blame) Oprah. The influential former talk show hostess bought a 10 percent stake in the weight management company, sending its shares up from $6.79 to $18.25 in as few as two trading sessions.

This is hardly the first time one of Oprah’s endorsements, whether verbal or monetary, has lifted a struggling business or product. There’s even a name for it: the Oprah Effect.

No matter your opinion of Oprah—her politics, her tastes—you have to admit that she’s a phenomenally savvy businesswoman, whose rags-to-riches success has helped make her one of the most powerful women in not just the U.S. but the world. As such, it’s important for investors to pay attention to her and other such “smart money” influencers. Their decisions often have the power to move markets.

So what’s moving gold right now?

Quite a lot, actually, from widespread doubts of a 2015 interest rate hike, to strong seasonal demand in India and China, to Russia’s military action in Syria. Gold also received a huge endorsement recently from billionaire Paul Singer, CEO of Elliott Management Corp., who said that the precious metal “should be a part of every investment portfolio, maybe five to 10 percent.”

(I always recommend 10 percent: 5 percent in gold stocks, 5 percent in bullion, then rebalance every year.)

But as I discuss in a previous Frank Talk, perhaps the most significant mover of gold right now is the weakening of the strong U.S. dollar against other world currencies. Gold and the dollar share an inverse relationship, and for the past year, the greenback has been putting pressure on the yellow metal, not to mention other commodities and natural resources.

Now that the dollar is showing signs that it’s starting to turn, however, gold is starting to turn heads.

Watch my video below for further insight into what’s moving gold.

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