Use Stellar's built-in decentralized exchange for crypto, forex, or securities. While investing in the crypto market, it doesn't take long before you run across Stellar Lumens. What Is Stellar? The Stellar network is an open-source, distributed and community-owned blockchain network used to facilitate cross-asset transfers of value. Stellar is an open source, decentralized protocol for digital currency to fiat money transfers. XLM is the currency symbol for Stellar Lumens, one of the most intriguing cryptocurrencies of today that is backed by some major players in tech and business.