Is CoinMarketCap correct?

Could you please clarify for me, is CoinMarketCap really accurate? I've been relying on it for my crypto investments, but recently I've noticed some discrepancies with other sources. Is there a chance that the data on CoinMarketCap might be outdated or incomplete? Could you provide some insights into how they gather and validate their information? I'm really curious about the reliability of this platform as it's crucial for my financial decisions. Thank you in advance for your expertise and assistance.