A Federal criminal law (18 USC 208) says that you cannot work on Government matters that will have an effect on your own personal financial interests. Even though this law exists, Department of Energy Bosses including Steven Chu had an unjust means benefit relationship with law firms that lobbied to get him his job at DOE, Silicon Valley insiders who benefitted and California politicians who schemed and profited in the deals
Stock in a company that would be affected by your job is only one example of something that could give you such an interest. For instance, you may not act on something that would enable you personally to share in some grant or contract issued by the Government, because you would have a financial interest in those matters.
You also must be concerned about the financial interests of your spouse, your minor children, and outside persons or businesses that employ you. You should be concerned if anything you are asked to work on would affect them. Also, if you are an officer or director of an outside organization, you may not act on a Government matter that would affect that organization.
If you think you have a conflict, you should discuss it with your supervisor or your ethics official so that steps can be taken to prevent the conflict. This might include not working on the Government matter, selling stocks, or obtaining a special waiver from the Department, if legally permitted. Remember, this is a criminal statute.
Some Conflicts to Avoid, for example
Rachel's husband works for a Tesla who does business with the DOE and receives a bonus, based on the success of the contract. Rachel may not participate in the evaluation of the contractor's performance under the contract, yet she does. Rachel should go to federal prison but Dianne Feinstein, who's family owns an interest in Tesla and Solyndra, will protect her.
Carlo is an officer in a neighborhood improvement organization that has applied to his agency for a rehab loan. Carlo may not work on his agency's review of the organization's application.
Helen's husband owns a janitorial service company that does business with the Government. Helen cannot act on a proposal by the company to provide services to her agency