- Today was a fairly strong risk-off session. $NDX fell 0.85% and $SPX 0.75%, while higher-beta AI infrastructure and optical names were hit much harder: $SIVEF -8.95%, $AXTI -6.18%, $AAOI -5.55%, $NVTS -4.98%, and $LWLG -4.53%. - Rates were the key driver. The September U.S. Composite PMI rose to 58.4, the highest since July 2021, while the 10-year Treasury yield jumped roughly 14 bps to 5.106%, its highest level since 2007. - Markets also increased the implied probability of another Fed hike in October from 53% to 66%. That is particularly painful for high-multiple semiconductor and optical names whose valuations depend heavily on future growth. - Rising oil prices and Middle East risks added another layer of inflation and rate pressure. Reuters similarly attributed today's weakness to the combination of higher oil prices and Treasury yields. - Just on Monday, the SOX index surged 4.3% and the Nasdaq reached a record high on renewed AI enthusiasm, so today's rate shock likely triggered amplified profit-taking in recently strong AI infrastructure names. > This looks much more like a duration/beta selloff than a breakdown in the optical or AI infrastructure thesis. $LITE fell only 0.92% and $MRVL 0.56%, while smaller, higher-beta names such as $AXTI, $AAOI, $SIVEF, and $LWLG dropped 4-9%. > The relative strength in $LITE and $MRVL is worth watching. The market was not indiscriminately selling AI connectivity, but rather aggressively repricing the names with greater liquidity and valuation risk. > I would therefore frame today less as an "optics problem" and more as a test of how aggressively a 5%+ 10-year Treasury yield can compress AI infrastructure valuations.