Corporate dealmaking, an important market for Wall Street financiers who advise both buyers and sellers, offered little to crow about in early 2016. There were fewer deals and for lower prices, thanks to a toxic mix of global volatility and economic weakness. But one area where investment bankers still have bragging rights is how their businesses stack up against each other. League tables from The Deal, a subsidiary of TheStreet, gauge which firms fared the best in a particularly challenging quarter, starting with JPMorgan Chase. The storied New York bank led its rivals in advising on transactions of $100 million or more involving at least one U.S. company.