Major stock indexes held onto mild gains Thursday despite the U.S. government shutdown, and small-cap gauges finished practically at session highs, a promising sign for the five-month-long confirmed uptrend. Tesla (TSLA) stock reversed sharply lower despite strong delivery numbers. Meanwhile, Astera Labs (ALAB) and Advanced Micro Devices (AMD) triggered new follow-on buy points on the stock market today. Key large-cap…