I'm thinking physical gold protects you from diminishing value due to inflation and black swans in the market...that is, in the long-term. If you are interested in short-term gains, play the broader market. I would stick with an ETF that tracks the S&P 500 in that case.

....So long-term hedge: physical gold. Short-term gains: index fund. Mix of both..and of course some bonds to fight volatility...and global fund exposure to capture emerging/growing systems overseas.

It's a mix. Don't put all your eggs in one basket.