144 0002009130 XXXXXXXX LIVE 0001999480 ALTO NEUROSCIENCE INC 001-41944 650 Castro Street, Suite 450 Mountain View CA 94041 6502000412 NICHOLAS SMITH Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

134886 3596060.76 39242104 09/29/2026 NYSE Common 09/29/2026 Exercise of Stock Options Issuer N 134886 09/29/2026 Cash Y The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale. 09/29/2026 06/30/2026 /s/ Nicholas Smith