Billionaire Gautam Adani has climbed to the 15th spot in the Bloomberg Billionaire Index (BBI) as of December 6, reaching within close distance of India's and Asia's richest man Mukesh Ambani.With net worth of $82.5 billion, the Adani Group founder is now the world's 15th richest person and the second richest Indian and Asian on the list. He has gained $12.3 billion from the last list position, but lost $38 billion year-to-date (YTD) – most of this loss can be attributed to the wealth bleed during the Hindenberg allegations.In January 2023, Hindenburg Research, a New York-based short seller, accused the Adani Group of prolonged stock manipulation and accounting irregularities. These claims were refuted by the Adani Group. Subsequent to these allegations, declines in the stock prices of Adani Group companies resulted in a staggering decrease of almost 60 percent in Adani's personal fortune, plummeting by up to $69 billion.Ahmedabad's Adani Group, led by Gautam Adani, stands as a key infrastructure conglomerate in India. It owns the nation's largest private port and a prominent role in global coal trading. Adani Enterprises, the flagship company within the group, disclosed revenues amounting to $17 billion for the fiscal year concluding on March 31, 2023.Gautam Adani's wealth primarily stems from his ownership in six publicly traded companies affiliated with the Adani Group, the conglomerate he established.As per the BBI, Adani's companies and stakes (via promoter group and through the Adani family trust) include the publicly traded companies -- Adani Enterprises (68 percent); Adani Green Energy (56 percent); Adani Ports (63 percent); Adani Power (67 percent); Adani Transmission (68 percent); and Adani Total Gas (37 percent).Meanwhile, Reliance Industries chairman Ambani retains his topmost Indian spot on the list at the 13th spot with wealth of $91.4 billion. He has gained $1.01 billion since the last change and added $4.33 billion to his wealth YTD.Rounding up the Indians in the Top 50 of the BBI are Shapoor Mistry with $32.8 billion at 41st spot and Shiv Nadar with $30.7 billion at the 45th position.