It is said to be a good practice to avoid trading near the market open / close as the market is volatile around that time.
(mentioned e.g. here)
I think it would be reasonable if autoinvest orders were executed at least 30 minutes after the market opens (and optionally, with a random delay so that the large number of users buying at the same time do not impact the market price)
To be fair the slight variations in that time of purchase would so insignificant if you are trading long term which I assume most people using autoinvest will be.
To be fair to T212 and the Autoinvest feature of Pies, I have not seen such an issue of volatility since all the orders are completed OTC. so even if the Stock exchange is seeing a bit of volatility, those of us on T212 usually aren’t so volatile and thus we still get decent prices that are as if we had bought later in the day,
As well as the volatility issue (arguably offset by higher liquidity pros), my main advantage would be wanting my pie transactions to occur simultaneously with no pending buys/sells.
George’s reply is spot on, unless you are trader, you dont care when market order executes. On some day you will hit +5% price on some -5%, over long run it irones out.