First, what is USDC?
USDC is a Stablecoin - a coin whose value is pegged to the US dollar. To understand more about Stablecoins, feel free to read this article on Gemini.
USDC is backed by fully reserved assets. For more details, check out this article on What Makes Stablecoins Like USDC Stable?
What does the Holdings tab show in my Securitize iD Account?
Once you’re logged in, on your holdings page you’ll see any Security Tokens you’ve purchased through Securitize and where the Security Tokens are located (Either your Securitize iD account or a whitelisted wallet).
Why can’t I see my USDC in my Securitize iD Account?
The holdings tab only shows Security Tokens you’ve purchased through Securitize. It won’t show USDC since USDC is a Stablecoin and not a Security Token.