On a day when the markets are otherwise flat, Citigroup (NYSE:C) shares are trading up roughly 0.5% halfway through the trading day, seemingly on no news other than some changes at some senior positions at the bank. The stock move is slightly less than its median daily move over the past 12 months, so it was to be expected, but let's take a closer look at those changes and what they could mean for the future of the bank.

But first, the sector
The rest of the Big Four banks have also stayed put for the most part this morning:

Citigroup shouldn't react as much as the others to housing data set to be released this week, but it doesn't make that information any less important for people that keep an eye on banks. As the overall economy continues to improve -- housing is only one measure to look at -- profits at big banks should continue to reap the rewards.

Senior shuffling at Citi
With the departure of CitiMortgage CEO Sanjiv Das planning on leaving the bank to pursue "other opportunities," Citibank CEO Michael Corbat announced a new leader at that division, prompting a shuffling of the deck at some of Citibank's most senior positions. Jane Fraser will move from the CEO seat at Citi's private bank into Das' old position. Mark Mason, current CEO of Citi Holdings, will take over the private bank, while Francesco Vanni d'Archirafi goes to Citi Holdings.

Citi Holdings could perhaps be the most important position of these moves, as the division manages all of the non-core assets that Citigroup is winding down or selling. At the end of the previous quarter, Citi Holdings accounted for 8% of the bank's total assets, a fairly significant amount. Vanni d'Archirafi will look to continue the work of Mason, who managed to reduce the account 29% over the previous year, allowing the bank to continue to focus on its core businesses.