I feel like there is probably a better way to specify what is a "tech company" as "IT company" doesnt make much sense to me. Qualcomm, TSMC, or ASML don't scream IT to me they are semiconductor companies.
Stock market value, by which you mean market cap, isn't as accurate a way to value a company as their market cap plus debt. If I have a company with $100b in debt owned by private bond dealers, and $1b in public shares, my company is worth $101b, whereas you're saying it's worth $1b. I also think you should subtract the cash or other liquid assets they have on their balance sheet.