Determination of the current worth of an asset. The asset to be valued can be either a real asset, such as a business, or a financial asset, such as a bond or an option. The simplest method of valuation is to observe the trading prices of similar assets. If no similar assets exist it may be possible to construct a portfolio of assets that are similar and apply a no-arbitrage argument. This is the basis of binomial pricing and the Black–Scholes equation in finance. Further alternatives include the evaluation of discounted cash flows and expert opinion.