Yes correct, but most of the trades are the major indices, forex and stocks. For the most cases the market maker give you liquidity.they may seem like small stakes but in some illiquid markets they may actually not be. not every underlying market has an endless stream of liquidity. some have close to none, some have just a side, some are RFQ. you need to understand what your spreadbet stake converts to in notional and then see what the depth of liquidity is in the underlying to judge what is 'small' and what is actually market size.