https://www.vice.com/en_us/article/k7wyew/wheat-futures-are-the-hottest-stock-on-wall-street

Fear over a disruption in global exports of grain from Russia and Ukraine have seen the price of wheat skyrocket on commodities markets.

Last week, Teucrium Wheat Fund, a wheat-based commodity ETF, had to stop creating new shares following soaring investor demand. The fund only has a finite number of shares it can sell investors—7.4 million—and when enough people expressed interest in cashing in on its booming value, the ETF reached its threshold and began trading at a significant premium over the actual value of the fund.