In the current BitSharesX design:
1] Trading occurs in a centralized market somewhere (although price discovery / trading activities are distributed, the NYSE / CME / etc. are centralized).
2] This trading produces information, namely a market price.
3] This price is used (for trades, settlement, margin calls) in BitSharesX.
BitSharesX seems to need  like a plant needs water. Does it?
What would happen if BitSharesX trading volume / value-storage grew to exceed or replace that of the public gold market? What would BTS traders use to establish the price of gold? If individuals disagreed with the price and began trading a new price, how would BitSharesX learn about this? Say, for example, gold miners selling Gold at a low price to a distributor, who ships gold to US markets where it is sold at a higher price. NYSE prices for gold assume the option to pick up the gold at (for example) a New York Exchange approved vault, standardizing the grade and location. BitGold would be digital, though, so which location's price would be used in this case?
What if all traders "waited to see what other traders decide to do"? What other strange phenomena might we expect at 50%, 51%, 100% replacement?