Are traders and speculators to blame for increasing poverty?

Despite making excellent scapegoats for bad public policy, debunking the myth that speculators harm the poor (ASI):

On the one hand the most limited version of Doane's thesis—that speculation increases prices—is undeniable. When speculators buy into the market, they raise the price then. But the overall case makes little economic sense. If speculators' influence is big enough to boost prices when they buy in, it is big enough to cut prices when they sell out. That is, speculators both add to, and take away from, prices.

A speculator makes money by buying in times of relative plenty, when prices are low, and selling in time of relative scarcity. For helping society ration effectively—making sure the differing scarceness of a good is reflected in its price, thereby improving individual decision-making—the firms earn a return. If a speculator, by contrast, buys in at the top of the market, reducing supply when it is most needed, and sells at the bottom, when it is least needed (relatively) they lose money. This is how the profit and loss system, in a good institutional structure, encourages and rewards socially-minded behaviour. And speculation should smooth volatility in markets. A jump in price will encourage sales from speculators, bringing the price back down. A dip in price will encourage speculators to buy, bring the price back up. This result dates back to a 1953 paper from Milton Friedman, which is hard to find online, despite being cited 2411 times according to google scholar.