Speculators:
are a key source of inflation.
move resources from poor countries to rich counties.
move resources from periods of low-value use to periods of high-value use.
serve no important economic function, except buying low and selling high.
Speculators primarily "move resources from periods of low-value use to periods of high-value use." This function is important in financial markets and commodities trading, as speculators help to allocate resources more efficiently by anticipating future price movements and adjusting supply and demand accordingly.
While speculation can have various effects on markets, including contributing to volatility and potentially influencing inflation, their main economic role is to provide liquidity and facilitate price discovery, which can help ensure that resources are used where they are most valued.