Physical investment Gold has a couple of advantages.
1. Its VAT free .
2. It will likely never get wiped out as an investment : its always going to be worth something even if you make a loss.
3. It seems to track a number of indexes according to the tinfoil hat brigade. Housing , food etc. So can be used as a hedge .
What I used to do was watch the Nymex mainly and put buy or sell orders into Goldmoney . You get a 5minute countdown with the price fixed so can cancel if the price is going the wrong way or dump at a higher price if the market is in freefall.
I often used to dump at the opening and buy back when the price had dropped. Whilst I made some money this way I barely broke even. Just buying on the dips and leaving it would have been more profitable in the long run. However I judged my get out perfectly to within a day of the market tanking back in 2009. Walked away but you can make some money if you can afford the time to actively watch the NYMEX and to a lesser extent the LME.
Also I found watching the price of silver tended to lead gold by maybe 30minutes or so but there is a lot of tinfoil hat nonsense out there on the forums. Kitco was what I used to watch the market.
I never got into shorting , just buying and selling physical . I made about 25% profit from a £60k initial pot in about two months . I’d probably have made closer to 30% just by sitting back but I doubt I’d gave judged my exit as well without having got my hands dirty for the two months. The market is a different beast now though. I might give it another go.