Guests attend the Future Investment Initiative in Riyadh on Oct. 28. Photographer: Fayez Nureldine/AFP/Getty Images Even before Saudi Arabia’s annual finance conference began, Wall Street’s biggest names were already signaling their intent. Citigroup Inc. unveiled its new regional headquarters in Riyadh, while Barclays Plc said it would return to the kingdom a decade after its exit. As the Future Investment Initiative got underway, Goldman Sachs Group Inc. Chief Executive Officer David Solomon said the b ...