Some cryptocurrencies that you can invest in with $15 or less and have excellent growth potential:

1. **VeChain ($VET )**: Aims to improve logistics and supply chains.

2. **The Graph ($GRT )**: Works as an independent data organization protocol, making it easier to retrieve data on networks.

3. **Hedera Hashgraph (HBAR)**: Uses Directed Acyclic Graph (DAG) technology to improve speed of operations and scalability.

4. **Chiliz ($CHZ )**: Provides a platform for engaging with arts and sports, allowing sports teams to issue tokens to fans.

Will I invest in it?