Cast bars refers to gold poured into a mould, which results in a distinctive round-edged look. It is often the cheapest form of gold, but to ensure a good resale price, make sure that you are buying a brand that is well accepted in the market. Most investors buy gold bullion with the intention of preserving wealth and making a return on their investment. Where the larger unit size gold bars or silver bars offer the best value when buying, they do not necessarily represent the best value when it comes to selling your gold or silver at a later date. Smaller unit gold bars such as the 1oz, 50g and 100g bars, and in particular gold coins and silver coins offer greater flexibility at resale. There are many reasons where this flexibility would come in use, releasing part of your investment for quick access to cash, or perhaps part-selling which is often an effective way of getting a maximum return on investment. Over time, individuals often want to change the balance of their portfolios, for example an investor may have 20% of their liquid wealth held in a 1 kilo gold bar, but want to release half of this to reinvest in stocks. At this point, the investor would either have to sell their entire gold bar or leave it and miss out on the other potentially lucrative investment opportunities. However, if they had originally invested in ten 100g gold bars, they could have easily sold half the bars to gain instant access to half of the money. Better still, bullion coins represent even greater flexibility and are a very popular option for new and experienced investors alike who are mindful of this and anticipate selling part of their bullion in the near or distance future. Gold coins are available in a variety of sizes such as 1oz, 1/2oz, 1/4oz and 1/10oz making them highly versatile, easy to store and ideal for trading if the banking system did ever collapse.