If the value of your property goes up or down but you’re not intending to buy more shares, remortgage or sell at that time, it will have little impact.  When you do come to remortgage, the value could affect the amount of the property’s value you’re borrowing. This means you could pay more for your mortgage if the percentage has gone up.  If you’re buying an extra share, a fall in the value means the cost of this will be less than it would have been at its original value. On the other hand, if the value has gone up the cost of the share will too.