Usually tech companies/stocks are valued using one of the two methods:
DCF (discounted cash flows) method that is sensitive to interest rates raise (if rates up value down)
EBITDA or revenues multiples are sensitive to interest rates as cost of debt raises and profitability worsens if internet rates increase.
why on the news it's usually mentioned that tech valuations are more negatively affected by an interest rates increase versus other sectors?
If we talk about tech stocks in general, a majority of their value is tied up in more distant cash flows / terminal value in a standard DCF analysis. So if interest rates go up, the more distant cash flows are impacted more due to the e^(-rt) discounting factor.
The reason tech stocks are seen as 'expensive' is because the P/E ratio for example is measured against next years earnings. WHen we measure it on projected earnings 4 or 5 years later, the P/E comes down to normal levels. this is one indication that tech stocks are valued for more distant earnings/cash flows, and also the reason for their higher interest rate sensitivity.
Edit: Lets say we start with 100 units of current earnings for 2 companies A and B. Company A annual growth rate = 20% and Company B annual growth rate = 3% For simplification purposes, let us consider the same discount rate for both companies of 5%.
Let us simply consider the next 2 years. Company A posts 120 and 144 units and company B posts 103 and 106.09 units of earnings for Year 1 and Year 2 respectively. Let us consider 2 scenarios for both companies.
Scenario 1: Interest rates stay at current levels. Company A's DCF equation (without terminal value) is 100 + 120/1.05 + 144/(1.05^2) = 344.898 Company B's DCF equation (without terminal value) is 100 + 103/1.05 + 106.09/(1.05^2) = 294.33
Scenario 2: Interest rates go up, and discount rate increases to 6% Company A's DCF equation (without terminal value) is 100 + 120/1.06 + 144/(1.06^2) = 341.36 Company B's DCF equation (without terminal value) is 100 + 103/1.06 + 106.09/(1.06^2) = 291.58
If we see the % fall in discounted cash flows, company A has 1.02% drop while company B has a 0.93% drop in earnings. The difference just two years out may not seem much, but as you add more years, this difference increases.
Over the last decade or so, many enterprise technology companies migrated from the license revenue model to the subscription model, also known as SaaS.
Low inflation allows companies to amortize the substantial upfront cost of developing the software products over a long period of time while charging reasonable subscription fees.
With high interest rates, the present value of future subscription revenues is dropping faster than the industry's ability to raise prices in a competitive environment. The SaaS model hasn't been tested in a period of high inflation, and the market doesn't like the uncertainty.
"why on the news it's usually mentioned that tech valuations are more negatively affected by an interest rates increase versus other sectors?"
It's specifically long term interest rates that affect tech/growth companies, since their earnings are supposed to be heavy weighted towards longer maturities.
If short term interest rates spike, other companies, like energy or real estate, will be more affected.
