Stocks took a step back to begin the first full week of October, reversing course as rising bond yields lead most Big Tech stocks lower midday. On the flip side, the airline sector is experiencing some positive movement, especially after Barclays upgraded the North American Airlines sector to "positive" and hit Southwest Airlines (LUV) with a bull note. At last check, the Dow Jones Industrial Average (DJI) is down 413 points, while the tech-heavy Nasdaq Composite (IXIC) sports a triple-digit deficit of its own, and the broader-market S&P 500 Index (SPX) is also swimming in red ink. 

Elmira Savings Bank (Nasdaq: ESBK) is one of the best-performing stocks on the Nasdaq today, last seen up 67.4% at $22.60, following news that it will be bought by Community Bank System (CBU). The purchase is the latest to take place in a wave of consolidation in the banking sector and is worth around $82.8 million in cash. The stock is now trading at its highest level since 2014 and sports a 107.9% year-over-year lead.  

Aemetis Inc (Nasdaq: AMTX), meanwhile, is one of the worst-performing stocks on the Nasdaq. The security was last seen down 11.5% at $17.47, though the catalyst for today's negative price action remains unclear. The equity did surge to a five-month high late last month on news that it struck a deal with Delta Air Lines (DAL) to provide sustainable aviation fuel (SAF) to the flight giant. The $17 level continues to act as a floor for AMTX, while the 10-day moving average also sits just below as potential support. Year-to-date, Aemetis stock is up 610%.

Dropbox Inc (Nasdaq: DBX) is catching plenty of bearish attention today, with 3,106 puts exchanged so far, around triple what's typically seen at this point and well above the 1,582 calls that have crossed the tape. The most popular by far is January 2022 24-strike put, followed by 26-strike put from the same monthly series. Dropbox stock is down 4.6% at $28.09 at last check, though it remains up 24.8% in 2021. The 180-day moving average is keeping today's pullback in check, however.