Janus was the Roman god of polarities. I did not know there was such a god until I Googled. The definition makes me glad I never had any Janus mutual funds:
Janus-faced
Definition: [adj] having two faces--one looking to the future and one to the past; "Janus the two-faced god"
[adj] marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another; "she was a deceitful scheming little thing"- Israel Zangwill; "a double-dealing double agent"; "a double-faced infernal traitor and schemer"- W.M.Thackeray
[adj] having or concerned with polarities or contrasts; "a Janus-faced view of history"; "a Janus-faced policy"
Synonyms: ambidextrous, bipolar, deceitful, dishonest, dishonorable, double-dealing, double-faced, double-tongued, duplicitous, faced, two-faced
(from the
Hyperdictionary)