I have been in the market like 20 years. Is mostly about speculations in the early years of investment with some help using NTA, or dabble in Warrant plays. (updated for privacy) . Active portfolio is much more significant now.
Stock market do not works by "Annual Way" like I do in my annual bookkeeping. So I have annualized return figure of my investment life. However this is still important because performance needs to be closely monitored just like companies reporting their quarterly and annual results to keep management on their toes. If you take care of your quarterly, your annual result will be ok.
Assuming 2017 stays good, out of recent 11 years, I have three losses in 2008 (50% loss) , 2011(13% loss) and 2015 (5% loss). As you can see, Year 2008 is mind changing for those who are heavily invested. Is like from Ah Boys to Men lifetime event.
( Ignore this statement if you are not familiar with XIRR : The year 2008 is particular interesting because when I use XIRR to compute for my case, it can show 0% loss instead of 50% loss. This got to do with multiple solutions to the equation. This is easily caught since I have large absolute loss that year which therefore I easily tweaked the XIRR formula on the 3rd "guess" field with "-0.1" which point towards negative direction or I believe the proportion losses to my portfolio size. Usually this is not a problem)
This event teaches me about cut loss, war chest and what is fear about. Some people bounce back, some do nothing and some never return. For those who long, quite a few make huge profits after that miserable year.
There are many teachers in my investment journeys of which I keenly remembered three namely Warren Buffett, Dennis Ng and AK. And I do a Rojak from their advice. Surely there are other sifus and bloggers who influence my styles some. Last but not least, always remember many people are interested in your money. Learn to protect and do grow old with them.