Wall Street had looked primed to continue with the technical breakout from Tuesday, but only to be dealt a minor setback in yesterday's session. The Dow still closed at a record high but saw early gains erased while the S&P 500 fell slightly with the Nasdaq dropping off as tech shares lost their way.While the AI rally may not be as fragile as it would seem, investors are also finding it tough to fully shake off any concerns on AI spending. In particular, the massive amount of capital expenditure spent by big tech towards AI. And that once again raises the question of if their multi-billion dollar investments can eventually yield returns quick enough before the ugly side shows up.SpaceX was the latest company under the microscope in that regard, with the stock falling by over 13% yesterday. The firm announced on Tuesday that its capital expenditure has jumped sixfold to over $18 billion in Q2, with the majority of that going towards AI.That being said, it wasn't the only big name to see a notable drop. Google also fell by 4% with Microsoft, Amazon, and Tesla all posting over 1% declines. And looking to semiconductors and chipmakers, AMD also posted a 7% drop with Sandisk and Western Digital both falling over 5% before their respective earnings call. On the latter two, they are both down another 9% in after-hours trade as investors continue to demand more from forward revenue guidance.With great price surges comes great expectations.[Nasdaq 100 performance heatmap for 5 August 2026]All in all, it's still just a step back for now after the price breakout for the S&P 500 (and Dow) earlier this week. With bond yields coming off the boil and markets not needing to worry so much about the Fed until next month, there is some breathing room perhaps. That not to mention this little leak about Trump calling up Fed chair Warsh every now and then.For now though, it's still a delicate situation. As mentioned yesterday, markets have been pegged back every so often by AI spending worries throughout the year but have still managed to shrug that off come what may. There's no doubt that the momentum is seeing some signs of strain but the charts are not pointing to any major technical worries yet, at least in Wall Street.S&P 500 futures are up 0.1% today but Nasdaq futures are down 0.1%. That is making for a bit of a tepid mood ahead of European trading, with the focus and attention now turning towards the US jobs report tomorrow. This article was written by Justin Low at investinglive.com.