(Update with information about Netezza's buyout and impact on Radware.)

NEW YORK ( TheStreet) -- Despite a few ups and downs the major stock indexes are up about 1% year-to-date. Among the gains -- of which there were many -- a number of specific stocks are now considered overbought and may be ripe for a sell.

A stock is generally considered overbought when high demand unjustifiably pushes its price higher than its underlying fundamentals support. It may also mean the stock's price has risen so much, and usually on high volume, that an oscillator's upper boundary has been reached, according to Investopedia. That usually indicates the equity's price is overvalued and due for a pullback.

Taking this into consideration, TheStreet looked at the overall equity market and screened for stocks with a price-earnings ratio greater than 50 and a weighted alpha greater than 100, according to data from Barchart.

P/E ratios measure a stock's current price compared to its per-share earnings. The metric points to a stock's most fundamental level of valuation, explained Nicholas Colas, chief market strategist at ConvergEx Group. Lower P/Es indicate lower levels of valuation and better opportunity; higher P/Es mean good news about the stock has already been baked into its price.

Weighted alpha is the measure of how much a stock gained or lost over the past year with an emphasis on the most recent price activity. If the stock is up it will have a positively weighted alpha. If the stock price is unchanged its weighted alpha will be smaller. A stock price loss will yield a negatively weighted alpha. Barchart weights the metric, assigning more weight to recent activity, and less to activity at the beginning of the period. This rear-looking indicator demonstrates how much outperformance has already occurred, Colas said.

"It's very tricky to know if all this means you should sell or not," Colas said. "If you own a stock on this list, you likely already booked a gain on it and would be wise to think about when you want to sell. If you don't already own it you will have a higher level of risk buying it now because so many good expectations are already priced in for future results."

In other words, the market already seems to know the company's positive traits. After all, stock picking is all about matching what you know with what the market knows, and trying to outpace.

Here, then, is TheStreet's list of 18 most overbought stocks, from the least overbought to the most.

MercadoLibre

18. MercadoLibre ( MELI)

P/E Ratio: 73.24

Weighted Alpha: 101.3

Company Profile

MercadoLibre is an online commerce platform based in Buenos Aires, Argentina. It offers its users two principal services: the MercadoLibre marketplace and the MercadoPago online payments solution.

Income Statement

Net income rose 74.8% in the second quarter to $11.7 million, or 26 cents per share. Revenues jumped 28.4% to $52.5 million. Operating income margin widened to 35.8%, from 30.3% in the year-earlier period.

Balance Sheet

MercadoLibre has cash and cash equivalents of $31.6 million; long-term debt totaled $1.4 million at the end of 2009.

Stock Ratios

MercadoLibre sells for a book value multiple of 24.3, compared with industry average 2.48.

Analyst Ratings

Roughly 37% of analysts covering MercadoLibre rate the stock buy; 7.5% rate it sell.

eLong

17. eLong ( LONG)

P/E Ratio: 120.4

Weighted Alpha: 105.2

Company Profile

eLong is engaged in the provision of travel services, including hotel information and reservation services, airline reservations and ticketing, internet-related advertising and other related services in the People's Republic of China.

Income Statement

Second quarter profits dipped 1.1% to RMB 9.4 million, or $1.4 million at current exchange. Revenue jumped 45.2% to RMB 118.9 million, or $17.6 million.

Balance Sheet

eLong has cash and cash equivalents of $107.9 million.

Stock Ratios

eLong sells for a book value multiple of 2.6, compared with industry average 4.42.

EZChip Semiconductor

16. EZChip Semiconductor ( EZCH)

P/E Ratio: 53.24

Weighted Alpha: 108.2

Company Profile

Ezchip Semiconductor, based in Israel, is engaged in the development and marketing of Ethernet network processors for networking equipment. It also designs and produces network processors for high-speed networking equipment.

Income Statement

EZChip returned to year-over-year profitability with second quarter earnings of $2.2 million. Revenue grew 122% to $14.9 million.

Balance Sheet

EZChip has net cash of $83.3 million.

Stock Ratios

EZChip sells for a book value multiple of 3.2, compared with industry average 2.1.

Analyst Ratings

Roughly 52% of analysts covering Ezchip Semiconductor rate the stock buy.

Salesforce.com

15. Salesforce.com ( CRM)

P/E Ratio: 177.91

Weighted Alpha: 112.2

Company Profile

San Francisco-based Salesforce.com provides customer relationship management service to businesses of all sizes and industries worldwide and provides a technology platform for customers and developers to build and run applications.

Income Statement

Second quarter profits were flat year-over-year at 29 cents per share. Revenue rose 25% to $394 million.

Balance Sheet

Salesforce.com has cash, cash equivalents and marketable securities of $1.9 billion; long term debt totaled $450.2 million at the end of 2009.

Stock Ratios

Salesforce.com sells for a book value multiple of 12.3, compared with industry average 4.4.

Analyst Ratings

Roughly 51% of analysts covering Salesforce.com rate it buy; 3% rate it sell.

Riverbed Technology

14. Riverbed Technology ( RVBD)

P/E Ratio: 132

Weighted Alpha: 114.6

Company Profile

San Francisco-based Riverbed Technology has developed innovative and comprehensive solutions to the fundamental problems associated with IT performance across wide area networks (WANs).

Income Statement

Riverbed returned to year-over-year profitability with earnings of $6.6 million, or 9 cents per share. Revenue rose 38.7% to $126.2 million.

Balance Sheet

Riverbed has cash and cash equivalents of $134.8 million.

Stock Ratios

Riverbed sells for a book value multiple of 7.4, compared with industry average 2.8.

Analyst Ratings

Roughly 29.2% of analysts covering Riverbed rate the stock buy.

Netezza

13. Netezza ( NZ)

P/E Ratio: 163.79

Weighted Alpha: 119.1

Company Profile

The Marlborough, Mass.-based company is a provider of data warehouse, analytic and monitoring appliances. It is known for its flagship blade server-based appliance TwinFin. On Monday, Netezza said it agreed to be acquired by IBM ( IBM) for $1.7 billion, or $27 per share in cash .

Income Statement

Second quarter earnings more than tripled to $3.2 million, or 5 cents per share. Revenue rose 45% to $63.8 million.

Balance Sheet

Netezza has cash and cash equivalents of $66.6 million.

Stock Ratios

Netezza sells for a book value multiple of 6.9, compared with industry average 4.6.

Analyst Ratings

Roughly 91% of analysts covering Netezza rate the stock buy.

RPC

12. RPC ( RES)

P/E Ratio: 64.8

Weighted Alpha: 119.3

Company Profile

Atlanta-based RPC provides a range of specialized oilfield services and equipment mainly to independent and oil and gas companies engaged in the exploration, production and development of oil and gas properties.

Income Statement

RPC returned to year-over-year profitability with earnings of $31.6 million or 32 cents per share. Revenue nearly doubled to $252.9 million.

Balance Sheet

RPC has cash and cash equivalents of $3.7 million; long-term debt totaled $90.3 million at the end of 2009.

Stock Ratios

RPC sells for a book value multiple of 4.3, compared with industry average 2.1.

Analyst Ratings

Roughly 32% of analysts covering RPC rate the stock buy; 16% rate it sell.

Baidu

11. Baidu ( BIDU)

P/E Ratio: 89.81

Weighted Alpha: 124.5

Company Profile

Beijing-based Baidu is a Chinese language Internet search provider.

Income Statement

Second quarter earnings grew 118.5% to RMB837.4 million, or $124.2 million, or 35.6 cents per share. Revenue increased by 74.4% to RMB1.91 billion, or $283.3 million.

Balance Sheet

Baidu had cash and cash equivalents of $615.9 million at the end of 2009; long-term debt totaled $607,900.

Stock Ratios

Baidu sells for a book value multiple of 33.3, compared with industry average 3.6.

Analyst Ratings

Roughly 50% of analysts covering Baidu rate the stock buy; 5% rate it sell.

VMWare

10. VMWare ( VMW)

P/E Ratio: 126.72

Weighted Alpha: 125.1

Company Profile

Palo Alto, Calif.-based VMWare is a provider of virtual infrastructure software solutions from the desktop to the data center. It works with more than 1,300 technology partners, including leading server, microprocessor, storage, networking and software vendors.

Income Statement

VMware's second quarter profit jumped 129% to $74.5 million, or 18 cents per share. Revenue grew 48% to $674 million.

Balance Sheet

Cash and cash equivalents were $2.5 billion at the end of 2009; long-term debt totaled $450 million.

Stock Ratios

VMWare sells for a book value multiple of 10.8, compared with industry average 5.8.

Analyst Ratings

Roughly 30% of analysts covering VMware rate the stock buy; 6% rate it sell.

Radware

9. Radware ( RDWR)

P/E Ratio: 63.14

Weighted Alpha: 136.3

Company Profile

Tel Aviv, Israel-based Radware is engaged in the development, manufacture and sale of Application Delivery solutions that provide end-to-end availability, performance and security of business-critical network applications. Speculation that Radware was in the sights of either IBM or Hewlett-Packard ( HPQ) for a takeover cooled Monday after IBM announced it would acquire Netezza in a $1.7 billion deal.

Income Statement

Radware returned to year-over-year profitability with second quarter earnings of $1.4 million, or 7 cents per share. Revenue grew 29.9% to $35.2 million.

Balance Sheet

Radware has cash and cash equivalents of $22.9 million.

Stock Ratios

Radware sells for a book value multiple of 4.6, compared with industry average 1.5.

Analyst Ratings

Roughly 55% of analysts covering Radware rate the stock buy.

Opentable

8. Opentable ( OPEN)

P/E Ratio: 145.82

Weighted Alpha: 137.2

Company Profile

San Francisco-based Opentable provides solutions that form an online network connecting reservation-taking restaurants and people who dine at those restaurants. Its solutions are Electronic Reservation Book, for restaurant customers and reservation website for diners.

Income Statement

Second quarter profits nearly tripled to $2.6 million, or 11 cents per share. Revenue increased 37.2% to $22.5 million.

Balance Sheet

Opentable has cash and cash equivalents of $29.4 million.

Stock Ratios

Opentable sells for a book value multiple of 16, compared with industry average 2.5.

Analyst Ratings

Roughly 29% of analysts covering Opentable rate the stock a buy.

F5 Networks

7. F5 Networks ( FFIV)

P/E Ratio: 57.76

Weighted Alpha: 156.7

Company Profile

Seattle-based F5 Networks provides technology that optimizes the delivery of network-based applications and the security, performance and availability of servers, data storage devices and other network resources.

Income Statement

Fiscal third-quarter net profits grew 77.6% to $40.5 million, or 50 cents per share. Revenue rose 45.7% to $230.5 million.

Balance Sheet

F5 Networks has cash and cash equivalents of $143.8 million.

Stock Ratios

F5 Networks sells for a book value multiple of 8.4, compared with industry average 4.8.

Analyst Ratings

Roughly 43% of analysts covering F5 Networks rate the stock buy.

Arm Holdings

6. Arm Holdings ( ARMH)

P/E Ratio: 74.64

Weighted Alpha: 185.3

Company Profile

Cambridge, England-based Arm Holdings designs microprocessors, physical IP and related technology and software, and sells development tools to enhance the performance, cost-effectiveness and energy-efficiency of high-volume embedded applications.

Income Statement

Second quarter income rose to 21.9 million pounds, or $34 million. Revenue grew 54.3% to 100 million pounds, or $155.5 million.

Balance Sheet

Arm Holdings had net cash of 202.3 million pounds, or $314.5 million.

Stock Ratios

Arm Holdings sells for book value multiple of 6.5, compared with industry average 3.2.

Analyst Ratings

Roughly 20% of analysts covering Arm Holdings rate the stock buy; 27% rate it sell.

Netflix

5. Netflix ( NFLX)

P/E Ratio: 59.17

Weighted Alpha: 217.7

Company Profile

Los Gatos, Calif.-based Netflix is a provider of subscription service streaming movies and TV episodes over the Internet and sending DVDs by mail.

Income Statement

Second quarter earnings grew 34.3% to $43.5 million, or 80 cents per share. Revenue rose 27.2% to to $519.8 million.

Balance Sheet

Netflix has cash and cash equivalents of $107.3 million. Long term debt totals $200 million.

Stock Ratios

Netflix sells for a book value multiple of 43.5, compared with industry average 9.3.

Analyst Ratings

Roughly 19% of analyst covering Netflix rate the stock buy; 30% rate it sell.

Entropic Communications

4. Entropic Communications ( ENTR)

P/E Ratio: 107.5

Weighted Alpha: 220.9

Company Profile

San Diego-based Entropic Communications is a semiconductor company that designs, develops and markets systems solutions to enable connected home entertainment.

Income Statement

Entropic returned to year-over-year profitability with second quarter earnings of $3.1 million, or 4 cents per share. Revenue jumped 55.9% to $40.7 million.

Balance Sheet

Entropic has cash and cash equivalents of $41.3 million

Stock Ratios

Entropic sells for a book value multiple of 8.6, compared with industry average 2.2.

Analyst Ratings

Roughly 83% of analysts covering Entropic rate the stock buy.

Craft Brewers Alliance

3. Craft Brewers Alliance ( HOOK)

P/E Ratio: 73.55

Weighted Alpha: 225.3

Company Profile

Portland, Ore.-based Craft Brewers Alliance produces specialty bottled and draft products at its company-owned breweries and operates adjacent restaurants or pubs that promotes its products, offer dining & entertainment facilities, and sell branded retail merchandise. Its beer brands include Widmer Brothers, Red Hook, Kona Brewing and Goose Island.

Income Statement

Craft's second quarter net profits of $1.7 million, or 10 cents per share, were flat year-over-year. Revenue grew 4.2% to $39.6 million.

Balance Sheet

Craft Brewers Alliance has cash and cash equivalents of $11 million; long-term debt and capital lease obligations total $1.9 million.

Stock Ratios

Craft Brewers sells for a book value multiple of 1.9, compared with industry average 3.2.

Acme Packet

2. Acme Packet ( APKT)

P/E Ratio: 85.86

Weighted Alpha: 244.5

Company Profile

Burlington, Mass.-based Acme Packet provides session border controllers that enable service providers to deliver secure interactive communications-voice, video and other real-time multimedia sessions-across Internet Protocol network borders.

Income Statement

Second quarter profits soared more than 470% to $9.7 million, or 14 cents per share. Revenue jumped 62% to $53.3 million.

Balance Sheet

Acme has cash and cash equivalents of $90.5 million.

Stock Ratios

Acme Packet sells for a book value multiple of 9.1, compared with industry average 1.9.

Analyst Ratings

Roughly 50% of analysts covering Acme Packet rate the stock buy.

Radcom

1. Radcom ( RDCM)

P/E Ratio: 158.33

Weighted Alpha: 415.6

Company Profile

Tel Aviv, Israel-based Radcom develops, manufactures, markets and supports innovative network test and service monitoring solutions for communications service providers and equipment vendors.

Income Statement

Radcom returned to year-over-year profitability with second quarter earnings of $80,000, or 1 cent per share. Revenue grew 76.9% to $4.6 million.

Balance Sheet

Radcom has cash and cash equivalents of $2.4 million; long term debt totaled $170,000 at the end of 2009.

Stock Ratios

Radcom sells for a book value multiple of 16.4, compared with industry average 2.1.

-- Written by Miriam Marcus Reimer in New York.

>To contact the writer of this article, click here: Miriam Reimer.

>To follow the writer on Twitter, go to http://twitter.com/miriamsmarket.

>To submit a news tip, send an email to: tips@thestreet.com.

READERS ALSO LIKE:





>>See our new stock quote page.

Get more stock ideas and investing advice on our sister site, Stockpickr.com.
Disclosure: TheStreet's editorial policy prohibits staff editors and reporters from holding positions in any individual stocks.