The title refers not to finance but (in typically cutesy fashion) to urban relationships--the whimsical, haphazard couplings and un-couplings (over just a few days) of a few kookily neurotic, verbally precocious New Yorkers. Oster's central, Greenwich Village couple: actress Molly (a TV-commercial success, a theater washout) and non-selling novelist Bruce (a teacher at the New School), whose living-together setup has reached the ""Interrogative Stage""--as in ""Do you feel like making love?"" (not ""Let's make love""). And when Molly buys an answering machine from a handsome Crazy Eddie salesman named Jake, this seems to trigger a breakup, especially since Molly has gotten wind of Bruce's side-affair with a teenager. So Bruce goes off on his own: wallowing engagingly in self-pity over his non-career; witnessing public sex at a party; and then taking up with street acquaintance Sheffy--a divorcÃ‰e who wears a Sha Na Na jacket, collects MacDonald's coupons, and accidentally jabs her elbow into Bruce's eye (when her laid-back boyfriend catches them in bed). Molly, meanwhile, goes equally astray: after learning that gorgeous, wise Jake is into celibacy, she broods on a past affair (her lover's live-in ""daughter"" turned out to be a mistress); and she obsessively prepares to audition for the role of Rosalind in As You Like It--by calling herself ""Steve"" and going around in convincing male drag (so convincing that ""Steve"" gets beaten up by anti-homosexual teenagers in Central Park). And there's yet another quirky variation on sex-roles with Molly's commercial-artist pal Maria--who has suddenly decided to be a lesbian. . . but can't seem to stop flirting, outrageously, with men (including a Penthouse photographer and a 70-year-old bicycling fanatic). Finally, of course, Molly and Bruce--physically injured but emotionally looser (Bruce even cries)--do get back together; and this ending, like all the more serious moments here, seems hollow and unearned. But at his best Oster delivers breezily weird encounters and dialogues (the book is mostly talk--about orgasms, jogging, California, etc.) with a wryly observant trendiness that suggests a raunchier, less classy Laurie Colwin. And though less likable than Sally George's similar Frog Salad (p. 24), this episodic entertainment, loaded with local and topical references (Village habitats, rock music titles, movie stars), will offer sporadic amusement and recognition-pleasure to a youngish, Manhattan-wise audience.