A stroop is equivalent to 0.000001 XLM. It is the smallest unit of the XLM that can be recorded on the ledger. XLM is the native cryptocurrency of the Stellar Protocol. Stellar has a fixed supply of 50 billion coins. Stellar's ledger has a close time of 5 seconds and dynamic fees contribute to fast transaction speeds and low costs. At the moment, 25.13 billion XLM are circulating in the market. Each transaction on the Stellar network incurs a minimum fee of 100 stroops, equivalent to 0.00001 XLM. These charges prevent spammers from abusing the network, thus increasing its overall security