Protection from bank default / financial crises
The prices of artworks are not correlated with the performance of financial markets and this means that value of an artwork is protected against international financial crises or bank system default.
Cultural / emotional component
For art there is a strong cultural and emotional component and this means that very often collectors or wealthy people surround themselves with artworks simply out of pure passion or to increase their status symbol. This aspect helps to sustain the demand and therefore the price.
If the clients are well advised and chose the right artworks, the liquidity of market is quite high, especially if they are oriented towards historicized works of art that can boast a sufficient number of sales in secondary public markets.
In this case, clients can be confident about the price and be quite sure that the artworks will always and in any case be in demand by the market.