They have asked regulators for permission to sell active E.T.F.'s that disclose positions quarterly, as traditional mutual funds do.
Some companies are concerned that having to disclose positions would cramp the style of the manager of the corresponding mutual fund.
The Ethics in Government Act requires members of Congress to disclose positions they hold with any outside entity, including nonprofit foundations.
His firms largest publicly disclosed position is a $1 billion stake in Yandex, the Russian Google competitor.
The S.E.C.'s review of the requests does not address another potential disclosure problem: investors who use options and derivatives to mask their publicly disclosed positions.
Mr. Goldsborough says he thinks that disclosing positions may be less of a concern for bond managers like Pimco because less high-frequency trading occurs in bonds than in stocks and, thus, there is less chance of falling victim to front-running.
He did disclose her position with the Clinton campaign.
Mr. Emanuel plans to disclose his position on city finances in a speech sometime in February, said Ben LaBolt, his spokesman.
As for Mr. Ackman, he is not required by securities laws to disclose his position in shorting, or betting against, a company's stock.
Castorama's chief executive, Jean-Hugues Loyez, said Schroder Salomon failed to disclose its position as adviser to Compass Group P.L.C., whose chairman, Francis Mackay, above, also is chairman of Kingfisher.
And the disclosures themselves represent only a snapshot in time: an investor could sell shares a day before having to disclose a position and buy them back a day after the disclosure requirement.
