Fidelity manages 22 of the top 101 funds in 401(k) plans, second only to Vanguard's total of 31. Overall, retirement savers who have invested in the Boston-based fund giant's most popular offerings have fared well. None of the 22 Fidelity funds have been disasters, and a few have been strong performers.

As part of our series on the best mutual funds for your 401(k) retirement savings, we took a closer look at the nine actively managed Fidelity stock funds that made the list, and rated each as "buy," "sell" or "hold." We also evaluated the nine Fidelity Freedom target-date funds as a group. While we didn't rate the four Fidelity Spartan index funds on the list--500 Index (FUSEX), Extended Market Index (FSEMX), US Bond Index (FBIDX) and International Index (FSIIX)--these low-cost portfolios are all fine choices.

The nine actively managed stock funds are listed in order of their 401(k) assets, starting with the fund with the most assets, based on data from BrightScope, a consulting firm that rates and ranks retirement plans. Have a look.

Fidelity Contrafund: HOLD

Symbol: FCNTX

Assets: $111.8 billion

Expense ratio: 0.64%

1-year return: 15.9%

5-year return: 14.4%

10-year return: 10.4%

We are huge fans of manager Will Danoff, who has steered this fund for nearly 25 years, earning a 13.4% annualized return during that period. That beat Standard & Poor's 500-stock index by an average of 3.1 percentage points per year.

But the fund's size causes concern; it was the key reason we removed it in 2014 from the Kiplinger 25, the list of our favorite no-load funds. With $112 billion in assets, Contrafund is the largest actively managed fund in the country. When we added the fund to the Kip 25 in 2009, it was about half that size. (The typical large-company fund has $3 billion in assets.)

John Buonnano, an editor of the newsletter Fidelity Monitor & Insight, deems Contra a "conservative" growth option compared with other Fidelity funds. We agree. If you're looking for an aggressive growth fund, you can find better choices at Fidelity. If you already own Contra, though, you can feel comfortable holding onto the shares. Even with the fund's vast asset base, Danoff has continued to beat the typical large-company growth fund and has done so with below-average volatility.

Fidelity Growth Company: BUY

Symbol: FDGRX

Assets: $42.5 billion

Expense ratio: 0.82%

1-year return: 22.0%

5-year return: 17.2%

10-year return: 12.4%

This outstanding fund has been closed to new investors since 2006, so if you can buy it in your retirement plan, consider yourself lucky. You won't be able to buy shares otherwise.

How lucky, you ask? In 2014, when 90% of all actively managed large-company funds lagged the S&P 500, Growth Company, under longtime manager Steve Wymer, earned 14.4%, beating the index by 0.7 percentage point. Since Wymer took over Growth Company in 1997, the fund has returned 10.4% annualized, outpacing the S&P index by an average of 2.5 percentage points per year.

Wymer has always been drawn to technology and health care companies. At last report, he had invested 55% of Growth Company's assets in those sectors. But he keeps a fine balance between aggressively growing firms and established companies growing at a steady pace. The fund's top holdings include Apple; Salesforce.com, a leader in customer-relationship-management software; and biotech firm Regeneron Pharmaceuticals.

Fidelity Low-Priced Stock: HOLD

Symbol: FLPSX

Assets: $45.8 billion

Expense ratio: 0.82%

1-year return: 11.2%

5-year return: 13.7%

10-year return: 10.1%

Since its launch in December 1989, Low-Priced Stock has posted a 14.5% annualized return, which beats the Russell Mid Cap index by an average of 2.7 percentage points per year. For most of those years, Joel Tillinghast was the fund's lone manager. He still manages 95% of the fund's assets, but in 2011, he handed over 5% of the fund to six others. Today, "Team Joel" hews to the same formula of seeking high-quality, growing companies trading at bargain valuations--and at share prices of $35 or less at initial purchase.

There's just one problem: The fund's size is top-notch, too. Low-Priced Stock is $20 billion bigger than the next-largest actively managed midsize-company fund. As a result of the fund's expanding girth, the nature of its holdings has changed over time. It once focused on small companies and initially sought stocks trading for $10 or less.

Because of asset bloat, we no longer give the fund our strongest endorsement; we removed it from the Kiplinger 25 in 2014. But if you already hold shares, you don't have to sell them. The fund may not focus on small companies anymore, and it may outgrow midsize companies before long. But Tillinghast is a proven master at picking stocks. And he has adapted his management style to deal with the billions of assets: He now invests in any size company if he finds a good value. Large companies, including Microsoft, Seagate Technologies and UnitedHealth Group, are among the top 10 holdings. He also ventures overseas: Korean and Japanese companies, for instance, make up many of his larger-company holdings. At last report, about 34% of the fund was invested in non-U.S. stocks. And he holds more than 900 stocks, many of which are small companies with tiny positions of less than 0.01% of assets.

Fidelity Diversified International: BUY

Symbol: FDIVX

Assets: $25.4 billion

Expense ratio: 0.92%

1-year return: 7.7%

5-year return: 8.0%

10-year return: 6.1%

The first thing you need to know about this foreign stock fund is that 12% of its assets were invested in U.S. companies, at last report.

Why does that matter? For starters, it helps explain why Diversified International, Fidelity's biggest foreign stock fund, has performed relatively well in recent years. (U.S. stocks did better than foreign stocks in 2013 and 2014.) Over the past three years, the fund's 12.8% annualized return outpaced its peer group--funds that focus on large, growing companies--by an average of 2.9 percentage points per year. It also beat the MSCI EAFE index, which tracks stocks of large foreign companies in developed countries, by an average of one point per year.

William Bower, who has run Diversified International since 2001, has delivered consistently good results. The fund has outpaced or matched the EAFE index in seven of the past 10 calendar years. Bower searches for high-quality, growing companies with strong balance sheets. Over the past two years, the fund has handily outpaced the EAFE index and its peers, with a 12.8% annualized return.

Fidelity Balanced: BUY

Symbol: FBALX

Assets: $28.7 billion

Expense ratio: 0.56%

1-year return: 12.5%

5-year return: 11.0%

10-year return: 8.1%

Yield: 1.31%

As is typical of balanced funds, Fidelity's product tilts more toward stocks than toward bonds. Lately, Balanced has tilted big-time toward stocks, with 69% of its assets in them at last report. With the stock market rolling, that's been a wise move. Another good decision: More than 70% of the fund's stock assets have been in shares of large companies, which have performed better than small-company stocks in recent years. Balanced's five-year return of 11.0% annualized beat the results of 96% of its peers.

Running the show are Robert Stansky, who has led the stock side of the portfolio since 2008 (he has nine co-managers), and Pramod Atluri, Fidelity's former chief economist, who came on board in 2012 to run the bond portfolio. Since Stansky, a onetime manager of Fidelity Magellan, stepped in, Balanced has beaten its typical peer in every calendar year, including so far in 2015.

But on the bond side, Balanced is less risky than its rivals. It holds a similar mix of government, municipal, corporate and bank loans as its peers, but Alturi tilts the portfolio more toward debt with investment-grade credit ratings (triple-B or better).

Fidelity Puritan: BUY

Symbol: FPURX

Assets: $26.0 billion

Expense ratio: 0.56%

1-year return: 13.0%

5-year return: 11.0%

10-year return: 7.8%

Yield: 1.27%

At first glance, Puritan looks like a classic balanced fund, with 60% of its assets in stocks and 40% in bonds. But truth be told, Puritan takes on a tad more risk than the typical balanced fund. Has it been worth it? Yes.

Ramin Arani, who took over stock-picking duties in 2007, dials up the risk with big bets on technology and health care stocks; 22% and 19% of the fund's assets are invested in each sector, respectively. He invests in burgeoning biotech names, including Xoma and Geron, but balances them with more established names, such as Amgen and Gilead Sciences. Since Arani came on board, the fund has outperformed the typical balanced fund in every calendar year except 2008, when Puritan lost 29.2%, while its typical peer lost 28.0%.

Pramod Atluri, Fidelity's former chief economist, runs the bond side of the portfolio, though Harley Lank handles the fund's junk bond investments. At last report, junk (debt rated double-B or lower) made up 5% of the fund's assets and 14% of the bond portfolio, a bit greater than the high-yield allocation in the average balanced fund.

With Fidelity's stock and bond analysts behind it, Puritan has turned in reliable results over the years compared with its peers. Its five-year annualized return of 11.0% beat 95% of all other balanced funds.

Fidelity OTC Portfolio: BUY

Symbol: FOCPX

Assets: $13.1 billion

Expense ratio: 0.76%

1-year return: 26.5%

5-year return: 17.3%

10-year return: 13.4%

OTC Portfolio is often compared to other large-company stock funds that use the S&P 500 as a benchmark. But as its name suggests, this fund aims to beat the technology-heavy Nasdaq Composite index. That's why OTC Portfolio has double the exposure to tech stocks than the average large-company fund. According to Morningstar, the fund also holds more small and midsize companies than the typical large-company fund. Holdings in the fund have an average market value of $27.0 billion, compared with a $73.6 billion average market value for holdings in the typical large-company stock fund.

Since Gavin Baker became manager in 2009, the fund has returned 21.5% annualized, topping the Nasdaq index by an average of 1.4 percentage points per year. (The S&P 500 returned 17.6% annualized over that period.)

Just be sure to buckle up for the ride: Over the past five years, the fund has been nearly 20% more volatile than the typical fund that focuses on large, growing companies. Three of the fund's five biggest holdings are the usual suspects: Apple, Amazon.com and Google. The other two are Rackspace Hosting, a cloud-computing company, and Groupon.

Fidelity Blue Chip Growth Fund: BUY

Symbol: FBGRX

Assets: $20.3 billion

Expense ratio: 0.80%

1-year return: 22.4%

5-year return: 16.5%

10-year return: 10.5%

Sonu Kalra is a rising star at Fidelity. He took over Blue Chip Growth in 2009 after a stint as manager of OTC Portfolio. This fund takes on less risk than his previous charge, and it has $7 billion more in assets. The blue-chip mandate is on the loosey-goosey side. Kalra is charged with investing the majority of the fund's assets in companies that are members of the S&P 500 index or the Dow Jones industrial average, or that have a market value of at least $1 billion if they are not in at least one of those indexes. On top of that is the "growth" requirement: Kalra looks for firms with long-term expected earnings growth of at least 10%.

Kalra's experience at other tech-oriented funds, including OTC Portfolio and Fidelity Select Computers, is reflected in Blue Chip Growth. More than 30% of its assets are invested in tech stocks: Apple, Google, Facebook and Amazon.com are among the fund's top five holdings (Gilead Sciences, the biggest biotech company, is the outlier).

Blue Chip Growth's 21.3% annualized return during Kalra's tenure smashed the S&P 500 by an average of 3.6 percentage points per year. Of course, his ascension as manager closely coincided with the start of a powerful bull market that continues to this day. And in 2011--the only calendar year Blue Chip Growth lagged the S&P 500 since Kalra became manager--the fund lost 2.7%, compared with a 2.1% return for the index. That's a minor blemish in what otherwise has been excellent performance.

Fidelity International Discovery: HOLD

Symbol: FIGRX

Assets: $11.1 billion

Expense ratio: 0.93%

1-year return: 6.2%

5-year return: 7.6%

10-year return: 6.6%

On the surface, International Discovery looks like a decent-enough foreign stock fund. Since William Kennedy took over its management in late 2004, Discovery has returned 7.4% annualized, edging the MSCI EAFE index by an average of 0.8 percentage point per year.

But the fund's performance has been uneven. In five of the past 10 calendar years, International Discovery ranked in the bottom half of funds that invest mainly in large, fast-growing foreign companies. The fund's long-term record is above-average, though, because in four of those 10 years, it landed in the top 14% of its category.

Kennedy favors profitable companies with sturdy balance sheets. Compared with his peers, he favors smaller companies. At last report, one-quarter of the fund's assets were in stocks of small- and mid-sized companies, almost double the 13% that other large-company foreign stock funds hold. The fund also has 8% of its assets invested in emerging-markets stocks, including India's Yes Bank and Techtronic Industries, a Hong Kong-based power tools and equipment company.

Fidelity Freedom target-date funds: HOLD

Target-date funds are designed to be a one-stop investment solution: You invest your money in a fund with a date that's closest to the year you plan to retire, and the pros do everything else. They decide how much of your money should be devoted to stocks, bonds and other assets. And they shift the stock-bond proportion to a more conservative mix over time. These kinds of funds are now the default investment choice in many retirement plans. The biggest Freedom fund--2020--has $13 billion in assets. But are the Freedom funds, which hold $62.5 billion in total, worthy investments? Nine of Fidelity's Freedom funds, from target date 2010 through 2050, rank among the top 101 401(k) funds. For now, they are far from Fidelity's most impressive funds, but they are slowly improving.

Fidelity has been recasting the series for three years. The changes included the creation of a new brand of funds to be used exclusively for the Freedom line. Known as Series funds, they are run by some of the firm's best investors, including Will Danoff, manager of Fidelity Contrafund, and Joel Tillinghast, who runs most of Fidelity Low-Priced Stock. The firm also revved up the funds' glide paths--the change in the stock-bond mix over time--to be more aggressive. Now the amount of stocks in almost all of the Freedom funds matches or exceeds that of their typical peers.

But these funds aren't ready for prime-time yet. While the funds performed considerably better in 2014 than they had in previous years relative to their respective peer group, we want to see more consistent numbers before we give them our stamp of approval. Another concern is over-diversification. The 2020 fund holds 26 funds. U.S. stock exposure--45% of the fund's assets--is divvied up into 14 portfolios. On the bond side, there are eight funds, and some of the slices are razor thin. The 2020 fund has 0.5% of its assets, for example, in a bank-loan fund and another 0.5% in real-estate debt.

Bottom line: The Freedom funds have been disappointing. Of course, this may be the only target-date product offered in your 401(k) plan. In that case if you want a target fund, stick with Freedom. The funds could be better, but they're not awful.

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Nellie S. Huang is Senior Associate Editor at Kiplinger's Personal Finance magazine.