How risky is Polkadot?

Could you please elaborate on the risks associated with investing in Polkadot? As a cryptocurrency and finance expert, I'm keen to understand the potential downsides that might arise from investing in this particular blockchain platform. Is it subject to high volatility? Are there any regulatory concerns or security issues that investors should be aware of? Additionally, how does Polkadot's risk profile compare to other major cryptocurrencies in the market? I'm looking for a comprehensive assessment that can help me make a well-informed decision about investing in Polkadot.