This thread is full of inaccuracies on what is a very simple and well honed method, developed many decades ago. There is, imho, a proper way of doing it once a few choices are decided on at the outset. But some of what I read is not correct, full stop. Not enough energy (as some of you know I am in seriously failing health) to go through the errors in detail, but I will enhance a write up I keep on the subject and post it to any new unitisers interested by PM, if requested. Older unitisers can carry on doing it 'their way', ie plain wrong some of them, at their leisure. I say that because when I have posted PMs to various, even some experienced, unitisers on various mistakes/discrepancies I noted in their posts in the past, they basically mostly carried on doing it wrong anyway on some lame excuse, typically 'this is how I do it'.
I was lucky enough to be introduced to it in some detail in early 1980s by a visiting speaker from the City( from HTR iirc) to our then investment club, used it immediately, as treasurer and systems chap, to sort out members joining and leaving using acc units. We nearly all started to use it on our own portfolios. I must say that we did not have any trouble using the same method, although there were plenty of very sharp members well equipped (as investors and IT/mathematically) to comment and criticise, being mostly senior managers from industry and commerce.
I have unitised all our portfolios, both acc and inc since doing both is a doddle anyway while you are at it, and dozens of other portfolios for family and friends since 1982 and run a few workshops on the subject as part of a general finance and investment after hours 'class' I ran for some years in the 1990s for students, which was increasingly attended by their parents and lecturers as part of our community programme! One of my sons now runs one occasionally.
Whatever unitisation you implement should work identically if you re invest, partially re invest, or take all divi income. If it does not and requires changes as your needs change, then your system and method are wrong. Some of what I read will fail in that respect. Whatever type of investor you are, acc and inc units will both cope equally well with you portfolio(s) and work perfectly if properly implemented.
I would encourage any newish investor to consider unitising. Post the initial, one of, set up, it does not require ANY work beyond the normal recording of portfolio EVENTS as they occur. Proper system design is they key. In my career, in industrial automation/robotics/AI mostly, we came across many new employees or interviewees who had brilliant spreadsheet/IT, mechanics and mathematical skills(else we not have been interested in them), but so few who could design robust systems to save their life. We had to teach them that before they were of any use, and bear in mind that these systems were immensely complex and critical to end users, unlike portfolios which are very simple entities. They key was to get them to analyse before diving in. Good design starts by defining your required OUTPUTs, diving in with a spreadsheet to be re hashed ad nauseum is the source of disaster and hours of un necessary work. Data should be entered once and once only, if not, then your system is badly designed. Never store what you can calculate or extract anyway, it leads to extra work.
Good investing to all in 2019 and beyond, we certainly live in interesting times!
Les Mis beckons. Not a patch on the Jean Gabin film so far,