Take a look:
I debunked tastytrade studies many times.
We will let them to do their studies and will continue making money with real trading, not theoretical studies. We prove the sceptics wrong every day - just look at our performance page.
I haven't set them up yet. Will wait until Monday. Which is not great but I don't want to set something up and then have a weekend event negatively impact.
They take the mid of the spread. For example:
Calls are 2.00/2.20
Puts are 2.00/2.20
The straddle is 4.00/4.40, so the mid is 4.20.
Now you place a buy order at 4.20. The bid/ask becomes 4.20/4.40, so they present the new mid as 4.30. But the real mid is still 4.20.
Trading and getting fills with Interactive Brokers