Updated from 1:28 p.m. EST with new stock prices

Small-cap stocks traded in and out of the black Wednesday as analyst ratings and earnings forecasts brought about the biggest moves.

Shares of VistaCare ( VSTA), a Scottsdale, Ariz., provider of hospice care, jumped 18.4% to $8.30. Tuesday night, Odyssey HealthCare ( ODSY) announced it would buy VistaCare for $8.60 a share, or about $147.1 million. This morning, Deutsche Securities added to the good news by upgrading VistaCare stock to hold from sell. Odyssey HealthCare was trading up 46 cents, or 5.5%, at $8.90.

Meanwhile, Tampa, Fla.-based Syniverse Holdings ( SVR) rose 16.1% to $15.75. The provider of technology services for wireless telecoms announced Tuesday after the close that it expects 2007 revenue between $369 million and $371 million, up from $328.9 million in 2006. It also predicts non-GAAP income to range from $74 million to $75.3 million, up from $57.3 million a year ago. Analysts polled by Thomson Financial forecast $365.9 million in revenue and income of $72.7 million.

Also gaining was Knight Capital ( NITE). The Jersey City, N.J.-based investment brokerage posted fourth-quarter earnings, excluding items, of 50 cents a share, vs. 33 cents a share in the year-ago quarter, trouncing the Street's per-share forecast of 26 cents. The stock climbed 19.4% to $14.95.

On the losing side, California Pizza Kitchen ( CPKI) fell 17.7% to $10.10 after the announcing last night that fourth-quarter earnings would be lower than expected . The Los Angeles restaurant chain sees EPS of 16 cents to 18 cents, compared with previous guidance for 22 cents to 23 cents. On average, the Street is looking for 23 cents.

Aruba Networks ( ARUN), a Sunnyvale, Calif., enterprise mobility solutions company likewise sunk. Shares dropped 14.7% to $9.81 on a downgrade by Jeffries & Co. to hold from buy. Also falling on a downgrade, Quicksilver ( ZQK) lost 11% to $6.60. B. Riley & Co. downgraded the Huntington Beach, Calif.-based apparel company to neutral from buy.

More broadly, the Russell 2000 was gaining 0.4% to 699.89, and the S&P SmallCap 600 nudged up 0.4% to 362.88.