Gold would be a potential solution since it will not lose its buying power during deflation or inflation
. The value of gold might be high or low compared to other assets but the buying power is likely to remain rather unchanged. For example during the period of the gold standard in 1940s, you could change an ounce of gold to $35 and with that $35 you could buy a very nice suit. Today when the price of gold is around $1200 per ounce you can still buy a very nice suit with the same amount of gold, although numerically the price has gone up by 3430%.