Sentencing for federal crimes is governed by federal sentencing guidelines and a "severity points" system developed by the Federal Sentencing Commission. There's a very thick manual with lots of detail involved, but basically the process (omitting quite a bit) goes like this.
1. Determine the base offense level.
2. Make any changes due to "Special Offense Characteristics."
3. Add or subtract any "adjustments."
4. Apply the perpetrator's criminal history.
5. Add up all the points, read the sentence range on the chart.
So... when we read this:
A financial manipulation scheme cost American International Group investors at least $544 million, a judge has estimated...
We can play the Grand Prize Game!
1. Base offense level:
§2B1.1. Larceny, Embezzlement, and Other Forms of Theft; Offenses Involving Stolen Property; Property Damage or Destruction; Fraud and Deceit; Forgery; Offenses Involving Altered or Counterfeit Instruments Other than Counterfeit Bearer Obligations of the United States
2. Specific Offense Characteristics
If the loss exceeded $5,000, increase the offense level as follows:
More than $400,000,000 add 30.
(Apply the greatest) If the offense--
(C) involved 250 or more victims, increase by 6 levels.
...the offense (i) substantially jeopardized the safety and
soundness of a financial institution; (ii) substantially endangered
the solvency or financial security of an organization that, at any
time during the offense, (I) was a publicly traded company; or
(II) had 1,000 or more employees; or (iii) substantially
endangered the solvency or financial security of 100 or more
victims, increase by 4 levels.
there was a violation of securities law and, at the time of the offense, the
defendant was (i) an officer or a director of a publicly traded
company; (ii) a registered broker or dealer, or a person
associated with a broker or dealer; or (iii) an investment adviser,
or a person associated with an investment adviser; increase by 4 levels.
Subtotal: 50 points.
Without going any farther, assuming no criminal history, and ignoring any departures / negotiated deductions (which, we grant, a decent defense counsel would manage to obtain in size), we look to the chart and find:
43 points and above: life.
A.I.G. Fraud Scheme Cost Investors $544 Million, Judge Finds [Bloomberg]