Banking stocks were trading broadly higher on Wednesday as gains for heavyweight lender Standard Chartered were enough to offset weakness in the wider sector, with HSBC, Lloyds, Barclays and RBS trading in the red.Following a massive 16% tumble yesterday, emerging markets-focused bank StanChart was pulling back today, trading 9.08% higher at 1,340p in afternoon trade.It was revealed yesterday that a US banking regulator accused it of collusion with the government of Iran to hide transactions from authorities. The the New York State Department of Financial Services (DFS) said that a subsidiary of StanChart engaged in "deceptive and fraudulent misconduct in order to move at least $250bn through its New York branch on behalf of client Iranian financial institutions that were subject to US economic sanctions, and then covered up its transgressions."However, the company released a statement saying that well over 99.9% of the transactions relating to Iran compiled with regulations and the total value of those which did not was under $14m.Today, Credit Suisse said that the discrepancy between the two figures has worried investors and uncertainty surrounding the back could drag on for a while.Meanwhile, the automobiles and parts and fixed line communications categories were trading broadly lower on Wednesday on the back of heavyweight sector constituents going ex-dividend.Engineering group GKN dragged autos lower, while phone and broadband giant BT dampened the telecoms sector. From today onwards, investors will not have the right to each group's respective dividends.Top performing sectors so far todayIndustrial Transportation 2,239.22 +3.32%Banks 3,619.36 +0.75%Mining 18,473.86 +0.69%Real Estate Investment & Services 1,733.87 +0.38%Forestry & Paper 6,128.90 +0.35%Bottom performing sectors so far todayAutomobiles & Parts 5,010.48 -2.32%Fixed Line Telecommunications 2,572.88 -1.65%General Industrials 3,169.78 -1.60%Oil & Gas Producers 8,323.87 -1.25%Food Producers & Processors 5,953.58 -1.05%BC