This guy sums up how I think about tracking GLD. There are about 1,000,000 holders in GLD, and it is heavily traded. So you've got retailers and punters, none of whom are market makers - it is a lagging indicator, i.e. useless.
"ETF Holdings Provide Daily Snapshot Of Investment Activity
There is one aspect of gold ETFs that is perhaps a positive and negative at the same time – the daily reporting of holdings and the market’s interpretation, Christian said.
Before ETFs, “the gold market has never had a daily indicator of investor demand for physical gold,” he said. That changed since major ETFs, including GLD, post their statistics on their websites on a regular basis.
“That’s a good thing and bad thing,” Christian said. “It’s a good thing because you have a daily measure. But it’s a bad thing because a lot of people…have relied on daily changes of the ETFs as an indicator of investment demand. And the reality is the ETFs represent about 15% to 20% of net investment demand. They represent a subset of investors who don’t necessarily think the same way as the other 80% or 85% of gold investors.”
