Financial risk is different from economic risk. It is deliberate exposure to asset price changes. Building an exposure to a change in the value of an asset is not bad per se. But we have to distinguish between arbitrage and directional positioning. Arbitrage is an essential market force. Indirectly, it helps production and trade.
Directional positioning, instead, can amplify and even creates gaps in asset prices. It does so by acting on expectations of future price changes. Unlike in the case of arbitrage, these price gaps are notional – indeed, “speculative”. They are often large only because they are not suitably discounted for risk.