However, things may not be quite as straightforward from the point of view of a private investor. Given that in a liberalised market the marginal fuel (the one with the highest variable cost, i.e. gas) sets the price of electricity, the electricity price in a liberalised market tends to fluctuate with the gas price thus preserving a rather stable profit margin for investors in gas. In a market with regulated prices instead, investors in nuclear would benefit from a stable profit margin and investors in gas would have to cope with the volatility of their cost base.