A screen full of quotes may suggest that a derivative mirrors the market behind it. The quoted price works as a careful imitation of the underlying, and small differences appear in places that most newcomers never think to examine. Those differences accumulate, and they explain why participants watching the same asset on different platforms might see slightly different numbers.
Under a contract for differences, two parties agree to exchange the difference in the price of an asset between the opening and the closing of a position. No shares, barrels, or ounces ever change hands. The provider derives its quote from the price of the underlying, usually taken from the primary exchange or a blend of liquidity sources, and adds a spread. That spread is the first and most visible gap between the derived price and the price of the underlying asset. It widens or narrows with market conditions.
Trading hours create a second source of divergence. When a stock exchange closes, trading in its shares stops, yet many providers continue quoting the related product, using futures, after-hours activity, or their own estimates to set prices. During those windows, the quote serves as a projection of where the opening price might land, with no actual market behind it. A visible jump can appear when the exchange reopens, and positions held overnight sometimes absorb that jump in full. Futures add a further technical factor for commodities and indices. Some products on oil and major benchmarks are priced from futures contracts that have their own expiry dates. When a provider moves from one futures month to the next, the quoted price can shift by the difference between the two contracts, and some providers apply a cash adjustment to offset it, while others close and reopen positions at the new contract price. Participants reviewing the chart may then see a gap caused by the changeover itself, with no corresponding move in the market.
Financing costs separate holding the product from owning the asset. Positions held past the daily rollover usually pay or receive an overnight amount based on a benchmark interest rate adjusted by a provider markup. Long positions usually pay financing, while short positions may receive a reduced credit or even pay. The effect is small over a few days, although it can outweigh a modest price gain over several weeks. Corporate events trigger further adjustments. On the ex-dividend date, long positions typically receive a cash adjustment, often net of withholding tax, while short positions are debited the gross dividend. Providers make adjustments to the size or price of the position in order to ensure that it maintains its economic value in the event of stock splits, rights issues, and mergers. These mechanics are generally fair, although the timing and tax treatment can differ from those that apply to ownership of the actual shares.
Slippage and execution rules also matter. In fast markets, the quote displayed at the moment of an order can change within a second, and the fill can arrive a few points away. Some providers widen spreads around scheduled announcements, and others stop quoting altogether when liquidity disappears. Reading the execution policy before opening an account clarifies how a provider handles these moments.
These small differences do not require advanced mathematical knowledge to understand, they just require strict attention to detail. Participants who regard the quote on a contract for differences as a close approximation to the underlying are prepared for the case when the two prices diverge. Spreads, trading hours, futures rolls, financing, and corporate adjustments together account for the gap between the quoted price and the market it tracks.
