If you ask most investors what the hottest metal is right now, gold might be the first answer, but it’s not quite right. Silver exchange traded funds (ETFs) are ruling in their own quiet way, though the metal had a couple hiccups this week.

The woes started late Tuesday, when silver for December delivery dropped 6.3% to $27.15 an ounce after the announcement of higher margin requirements for silver futures, according to The Wall Street Journal. [Demand Propels Silver ETFs to Records.]

Minimum margins requirements for silver increased from $5,000 per contract to $6,500. Since many investors weren’t keen to put down more money, they sold and sent iShares Silver Trust (NYSEArca: SLV) south. [4 Ways to Get Silver ETF Exposure.]

The fund wound up sinking 3.6% and closing at a 6.2% discount to its NAV. On Wednesday, silver prices fell further but SLV surged 2%. What gives?

The disconnect between the performance of SLV, which holds physical silver and seeks to track the spot, and the spot price is due to the price discovery process after the markets are closed. Spot silver in London closes at 7 a.m. Eastern time, when the markets here are close to opening. So, in effect, SLV was trading in line with the news of increased margin requirements while the markets overseas were closed.