Because NoVo is non-custodial, it connects to your own account at a supported broker — Tradier or Alpaca for this comparison (you can also bring tastytrade as your data feed — see which brokers NoVo uses). Both here are legitimate, regulated brokerages, and the right choice depends on your priorities. Here's a practical guide (for a deeper broker-level comparison, see Alpaca vs. Tradier for options).
The shared foundation
First, what's the same: with either, you open and fund the account, you keep custody of your money, and NoVo connects via a trading-only API — the non-custodial safety holds regardless of which you pick. Both are real brokers you control; NoVo just routes your trades to whichever one you've connected. So this isn't a choice about safety — it's about which broker's account best fits how you want to operate.
How to think about the choice
Base the decision on the factors that matter for your trading: which broker you may already have an account with (simplest to use that one); their options-trading approval, fees, and commission structure for the volume you'll do; account minimums and features; and your own comfort and familiarity with each platform's ecosystem. Both support the SPY options trading NoVo does; the differences are in the account details and your existing relationships, not in whether NoVo works with them.
The safety is identical either way — your money stays yours. Pick the broker connection by fees, features, and which account you'd rather run, not by trust.
The practical answer
If you already have (or prefer) one of them, that's usually your answer — use the account you're comfortable with. If you're starting fresh, compare their current options approval, costs, and features for your expected activity and pick accordingly (and see the detailed broker comparison for specifics). Either way, you're connecting NoVo to your regulated account, keeping custody of your own funds — the choice is about fit, not about whether it's safe.