Who on Wall St. is contributing to Obama's campaign?

Several critics have questioned the sources of contributions to Barack Obama's campaign, one of these criticisms being that many contributions are coming from Wall St. firms.

Contributors to political campaigns are required to give the names of their employers and their occupations. Is anybody breaking down these contributions from Wall St. firms into those from executives and those from others, say janitors, clerks, accountants, and brokers. Consider the following:

More generally, this year's registration tilt is part of a broader shift since 2004 away from Republican affiliation, particularly among younger and Hispanic voters and among college-educated professionals in former GOP strongholds such as New Hampshire, Colorado, and the suburbs of Philadelphia and Northern Virginia.

- "Registration gains favor democrats", Washington Post, 2008-10-06

Could it be that many of the donations from Wall St. are from these young professionals? Could it be that the sum of their donations to Obama exceeds that of their executive bosses?