The Australian sharemarket and S&P/ASX 200 (^AXJO) has spent its first day of 2019 falling 75 points, with the likes of Australia and New Zealand Banking Group ( ASX: ANZ ) and Commonwealth Bank of Australia ( ASX: CBA ) being knocked down. As the ASX 200 closed today, shares in ANZ and CBA were down 2.4% and 2%, respectively. National Australia Bank Ltd. ( ASX: NAB ) and Westpac Banking Corp ( ASX: WBC ) were down 1.8% and 2.2%. Why Are CBA and ANZ Shares Falling? As is often the case, there appears to be little to help explain the sell-off of bank shares on the ASX. The only newsworthy update came earlier today. Rask Media's Jaz Harrison reported that the decline in house prices throughout 2018 extended into December, with Sydney and Melbourne house prices coming under pressure. Fairfax Media is calling it the weakest property market since 2008… that's debatable.