SPY meaning in Cryptocurrency ?

Tokenized stocks are tokenized derivatives that represent traditional securities, particularly shares in publicly firms traded on regulated exchanges. The key benefits of tokenized stocks include fractional ownership of traditional securities, 24/7 access to markets, and greater liquidity to name a few. These digital assets are backed 1:1 to traditional stocks, entitling holders to many of the same economic benefits of owning the underlying stock. Tokenized stocks are a tokenization of a digital total return swap contract (“TRS”) (similar to contracts for differences). The Tokenized stocks value is based on and collateralized with the underlying asset, a traditional security (typically a publicly traded equity) and the value of the digital asset is determined by the value of the traditional security. For example, they are collateralized by an equivalent notional amount of the traditional security (i.e., $100 of the debt derivative would be collateralized with $100 of the traditional security). This allows Tokenized stocks to mirror the economic performance of the applicable reference traditional securities. 

Bittrex Global itself lists tokens that represent derivative contracts collateralized by the underlying traditional equities. These tokens are backed by shares of stock powered by DigitalAssets.AG. They cannot be withdrawn from Bittrex Global or redeemed for the underlying shares. In the future, there may be ways to withdraw the tokens from Bittrex Global or redeem the tokens for the underlying stocks. For now, there are only spot markets for the tokenized stocks featured on Bittrex Global.

Swiss-based DigitalAssets.AG facilitates the tokenization of traditional financial assets. The firm brought stocks trading to another major crypto exchange in cooperation with German based CM-Equity AG as recently as December of 2020.