In the IS-LM equation, we have the investment function:

Where I use the Blanchard modification that lets investment rise with income, kind of an accelerator.

How can we reconcile the higher nonresidential fixed investment with higher interest rates, aside from the endogeneity of the Fed funds rate. One is to recognize that b0 is not necessarily fixed; we can think of that constant as changing exogenously. The example in 2024-26 is the increase in the prospects of AI for future profits. To see this, consider total nonresidential investment compared to ex-computers and software (normalized by GDP), and interest rates:

Figure 1: Nonresidential fixed investment to GDP (black, left scale), nonresidential fixed investment ex-computers and software to GDP (blue, left scale), the 10 year Treasury rate, % (red, right scale), and Fed funds rate, % (pink, right scale). NBER defined recessions shaded gray. Source: BEA, Treasury, Fed, NBER. 

Note that outside of computers and software, nonresidential fixed investment has declined as a share of GDP.