With the stock market in steady decline, it is increasingly important to review the investment decisions that you've made to ascertain that you only own stocks that you believe in for the long run. One of the most logical ways to conduct this investment review is to recall why you bought each stock that you own. Ask if your initial reasons for owning a company still hold true now.

Today, we review the decisions that we've made since the Drip Port launched in sunny 1997, and we consider the performance of each of our investments since day one. Our real-money portfolio has done well, typically beating the S&P 500 Index on a comparable, dollar cost average basis. However, this year has leveled our performance to near-flat (up 2.5%) since inception. Meanwhile, the comparable S&P 500 is now down (losing more than 6%) since our 1997 inception.

The stock market can erase itself like this. That's why you, dear fellow investor, should not have money in stocks unless you don't need that money for at least three to five years, and ideally (as you can see today) much longer.

Reviewing each of our purchases
We will do as you should do at home: Start with the oldest investment you hold, remember why you bought it (and write that down for future reference), and then realize whether that reasoning remains valid today. 

In 1997, we formed our investment strategy and then we looked for our first purchase. We considered a technology company that we understood: Intel (Nasdaq: INTC). After a few weeks, we decided to enroll in Intel's free dividend reinvestment plan. It was August 19, 1997 when we decided to buy the stock. Intel traded at $24.00 that day. As of today, it is at $26.50, up 10.4%, while the S&P 500 is up 18% since August 19, 1997.

Numerically, the investment has underperformed. Has the business met our objectives? Yes, with qualifications. We bought Intel for its dominance of a lifeblood product in the PC industry. Intel continues to dominate. However, its operating earnings have not grown much since 1997. Even so, we remain confident in Intel's long-term prospects as an efficient manufacturer.

A few months later, after studying the industry, we bought Johnson & Johnson (NYSE: JNJ). This buy was announced Oct. 8, 1997. The stock was $61 that day. It started today at $87, up 26% before dividends, while the S&P 500 has gained 15% over the same period. Numerically, this buy has succeeded. (Naturally, our cost basis in the stock is higher because we average in, but today we're analyzing performance since the purchase decision itself.) Meanwhile, Johnson & Johnson's business has shined. It has grown earnings per share 14% or more per year, proving wrong its many 1997 critics. The reasons we bought it -- diversity, growth, stability, ingenuity -- hold true.

On Jan. 30, 1998, we announced our intention to purchase Campbell Soup (NYSE: CPB). This has proven to be a mistake. On that day, the price was $53.50. Today it is $30.00, down 44%, while the S&P 500 has gained 14%. Fortunately, before summer's end of 1998, we stopped buying more Campbell Soup because the business wasn't performing, the stock price subsequently looked too high, and Campbell added fees to its Drip.

At the right price and right time, we'll sell our shares of Campbell due to the plan's fees and, even more importantly, because our reason for purchasing it -- modeling for 14% to 16% annual earnings growth based on the soup giant's dominance and new initiatives -- has proven faulty.

Next, on Sept. 16, 1998, we announced our plan to buy Mellon Financial (NYSE: MEL). It was $29.75 per share. Today it is $37.75, up 27% against an S&P 500 that gained just 6.7% over the same period. Mellon has delivered on double-digit annual earnings growth. We bought Mellon due to its superior return on assets and its management, both of which are even stronger today.

Finally, we announced our PepsiCo (NYSE: PEP) investment on July 12, 2000, at $39.75 per share. It's too early to say anything.

Where we stand and our next investments
We're comfortable with what we own and why we own it, even Campbell Soup, because we understand our mistake. Our reasons for purchasing our other four companies remain intact, or amplified. Given our confidence in what we own and why we own it, the stock market can do what it may. (Are you equally confident in what you own? You should be!) We own businesses in which we believe. We'll continue to increase our stakes.

Tomorrow, we'll send $50 to Johnson & Johnson and $50 to Intel for our April investment. We get much more stock for our buck than just months ago.

Overall, as a steadily investing portfolio, adding money every month to what had been a soaring stock market from 1997 to 2000, our performance is still favorable. We're beating the S&P 500 on a comparable basis (and even more so considering our relatively high start-up costs). If we were losing to the S&P 500 by a wide margin, we would need to reassess not only our investments, but our strategy.

High-growth study update
Following Rex Moore's excellent look at Cree (Nasdaq: CREE) on Wednesday, three companies (other than Cree) remain as potential high-growth finalists: Trex (NYSE: TWP), Gemstar TV Guide (Nasdaq: GMST), and Jabil Circuits (NYSE: JBL). We currently have nine finalists. We'll continue next week. Fool on!

Jeff Fischer has beneficial interest in all of the companies in the Drip Port. He also has beneficial interest in seeing the planet survive. The Fool has a full disclosure policy.