As the quarter's shareholding data comes in, we are seeing top superstar investors update their portfolios, as valuations change and some sectors - and stocks - fall out of favor. One of the key factors of a good portfolio is selling losers quickly rather than hanging on, hoping for a recovery. These are five stocks that lost favor with the biggest investors in the September quarter. 

1. MCX: Investor Rakesh Jhunjhunwala has sold this commodity exchange stock, reducing his stake below 1%. MCX significantly underperformed the index over the last year by 41%. However it gained sharply in share price since the beginning of October after Jhunjhunwala's sell. You win some, you lose some. 

2. Xchanging Solutions: Sunil Singhania's Abakkus Fund had increased the stake in this smallcap tech company between the March and the June quarters, but cut it in the September quarter. This was another underperformer relative to the index, with negative price to earnings growth over trailing twelve months.

3. Apollo Pipes: The reclusive investor Ashish Kacholia avoids the limelight, and has a great track record in his picks. His net worth has climbed steadily over the quarters he has been investing. A recent stock he sold is the pipes company Apollo Pipes, in which he previously held a 3.6% stake. Kacholia sold Apollo Pipes despite the construction sector being fairly bullish in its outlook over the next few quarters. The stock has been a stellar performer over the past year, with nearly 400% 1 year returns. 

4. Kolte Patil Developers: Investor Mohnish Pabrai's Pabrai Fund has cut his holding in a long held real estate stock (held since 2017), from a 6%+ stake held in the March 2021 quarter. While the company's stock has seen some recovery in share price since early September, it has overall been an average performer in the real estate sector. 

5. Som Distilleries and Breweries: This brewery stock has been down since its peaks in 2018, and the pandemic lockdowns continued to batter its performance. Investor Porinju Veliyath had reduced his fund's stake in the company to 1% in June 2021, and appears to have exited the stock in the September quarter. 

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