In following cases people tend to hold multiple stocks.
1)Sometimes the portfolio is so huge that by buying or selling in a single company becomes difficult from liquidity point of view.Fortunately I do not fall under this category.
2)Putting all your eggs in one basket is risky- Here we must understand that buy buying shares of different companies basically we put our eggs in same type of basket with same risk. Hence diversification means different asset classes like equity/gold/real eatate/FDS etc and not owning different company shares.
3)My aim for investing is to make serious money . I am looking at multiplying my present net worth ten times in ten years and anything less than that would be under achievement. Hence when I look at the company the first question I ask that can this grow ten times in ten years? Whether the business would be relevant after ten years? Whether management would be able to maintain competative age for that period?Can I sleep peacefully if share price falls 50% or increases 50%? Can muster courage of averaging at reduced price?If the answer is yes why not own single company?
4)Over a period of last few years some of the buy sale in my portfolio-
opto circuit-buy 80, sale 280
jubilant org-buy 80,sale 310
siemens healthcare-buy 320,sale 1400
spice tel-buy 31,sale 85
BOC india-buy 160,sale 290
Tata chem-buy 150,sale 320
Gail-buy 159,sale 390
petronnet lng-buy 78,sale 95
jb chemicals-buy 55,sale 110
alstom-buy 380,sale 410
glenmark buy 250 sale 310
kaveri seeds,buy 270,sale 360
AND SO MANYlike vivimed,GRP,TTK HEALTHCARE,IDFC,etc
ACGL,BUY 370,SALE 280
TIL,BUY 520,SALE 420
SANGHVI MOVERS,BUY 132,SALE 114
VINATI ,BUY 71,SALE 61
AND SO MANY like JP,PUNJ,GREMACH ,SINTEX ETC
Inspite of doing so many profitable trades portfolio went up just about 15% CAGR for last few years. Then I realised if we want to make serious impact to our net worth we should take very few but solid bets and do a 25 to 30% CAGR for about 15 years and I changed my investment policy and started taking these bets.
At the same time sometimes I do take trading bets like TBZ but gains are again invested in core portfolio.
But any how this has worked for me so far and only if it works for a prolonged period of 10 to 15 years then only I can say what I did was right. One should take bets in which he is comfortable and understands the rules and risks of game completely.