I will tell you the opinion about secure from a master of economics, Friedrich August von Hayek.You can learn what Secure currency could be holded.
In order to establish confidence for the public, it is necessary to set a target price and declare a reserve price so that its price will not fall below this price, and declare a maximum price so that its price will not be higher than this price. Regardless of the method, it is necessary to stabilize the price in this range . In particular, it is necessary to show real-time price and adjustment measures to the public to build confidence.
In order to prevent the possibility of the issuer from increasing the currency at will, it is also allowed to pay the amount of money issued by the issuer in the nominal amount of the currency of the issuer, or in the corresponding amount of other currencies as long as the value is equal to the market. This will give users a high probability of avoiding the fear of rising and falling prices.