Breaking Down An Option Contract Chart
Let's talk about the contract charts and things to think about when considering the various data points. Consider it an update to the March 2023 tweet seen here:
A basic order of operations:
1) More vol>OI?
2) What's the bid/ask skew?
3) What did the volume look like?
4) What % of vol was from multileg trades?
5) Notional value?
6) How many total 'trades'?
7) Would historical charting help my analysis?
8) ALWAYS look at the raw data.

This view can be reached by:
- looking up a contract in the Contract Look up
- clicking the contract's expiration date in the various feeds
1) Contract volume and open interest:
Volume and open interest are two of the main data points referenced when describing options activity.
On August 16th the $WMT 86.67 strike January calls had 3,785 open interest. During that session these contracts saw over 20,000 volume, which is quite a large number when compared to 3.785. This opens the door to the theory that there is a significant amount of options being opened on these particular contracts (since you can't close what isn't already open).
However not all volume is created equally. Consider the following image depicting the volume of 2 option contracts.

One contract has all the volume concentrated in a singular candle (to represent a singular trade) whereas the other contract shows the volume taking place throughout the day (smaller orders).
Keep in mind that volume and open interest are relative values. For example I'd consider 1000 volume a lot relative to 50 open interest. I might not feel the same way about 10,000 volume and 9,000 open interest.
2) What's the bid/ask skew?
The mechanics of the bid/ask spread are fundamental to interpreting options flow and are generally used to identify buyers and sellers.
Quick refresher: something with a bid of 1.00 and an ask of 1.10 can be SOLD for 1.00 or PURCHASED for 1.10.
87% of all volume being at (or closer to) the ask price would suggest heavy buying activity on these contracts. Tie that in with what we went over in "Contract volume and open interest" and you can start to piece together that large opening buys (keep in mind that not all BUY transctions are buys to open) are taking place.
3) What did the volume look like?
Recall that expertly drawn image of the 2 volume charts. The singular activity (or in the case of these $WMT calls the concentrated activity) is what we're looking for: a whale or several whales piling into a contract.
4) What % of the volume was from multileg trades?
Options contracts can be transacted on their own or as part of larger, more complex trades. Any trade with 2 or more components is considered a multileg trade.
Any trade that is transacted as part of a multileg trade is labeled with a trade code that is applied by the options exchange that executed the trade. The Unusual Whales platform receives data on every single options trade across all exchanges, and can thus identify what % of volume for any given contract was from a multileg trade.
In the case of these $WMT calls none of the 20,000+ contracts traded was from a multileg trade so we don't have to worry about these [likely long] calls (bullish) as being part of a call credit spread (bearish).
Meme for your enjoyment:

5) Notional value?
I mentioned earlier that volume and open interest are relative values. The overall value of the options flow is also relative. A $500,000 trade on AAPL is a relatively common occurrence, but $100,000 into a thinly traded small cap might be something to look further into.
6) Historical charting
A multiday lookback can be very helpful.
You can see activity on these very same $WMT calls for multiple sessions in a row.
Anyone remember that Roaring Kitty guy? Multiple days of $GME call flows seen here:

There are many more things that we need to consider when looking at flows but as it pertains to the contract charts I think the above information should get you quite far in your analysis.