Why is the portfolio to the right of CML/CAL a borrowed portfolio?
If you’re on the right side of the CAL, you’re in the territory of either unattainable or inefficent portfolios. I’m pretty sure you meant to ask, “why the portfolio to the right of 100% allocation to the risky asset (and still on the CAL) a borrowed portfolio?”
Think of it this way. How can you allocate more than 100% of the portfolio to the risky asset? So let’s say you have the risky asset assigned 130% of the portfolio. How do you ensure that the laws of portfolio theory remain intact? You must subtract 30% of the risk-free asset. This essentially means, you short (AKA borrow) 30% of the risk-free asset so that you can invest the additional proceeds into the risky asset. This is one way to go beyond where no man has gone before… i.e. >100% allocation to the risky asset. This is what the CFAI refers to as borrowed portfolio.
Taking this a step further: Beyond 100% allocation to the risky asset (and still on the CAL), there is a kink in the CAL. This is because you borrowed money to get to this juncture and whatever your rate of return is, it is dented because you must pay back to whoever you borrowed from at the risk-free rate. Think of this as shorting a stock. You borrow stock from your brokerage and they will charge you a fee (let’s say 2%). After you close the transaction and make a return of 10%, your overall performance is actually only 8% because you must pay the brokerage fee.
I’d say spend time on this and understand the nuances since this will show up again at L2 and L3.
I don’t have the L1 curriculum in front of me, so not sure I’m doing a good job explaining, but hope this helps.
Sure, it does. Thanks! Is there a place/forum/website (link) on the internet where I can visually see that “kink”?
The “kink” is defined and included in the CFAI books for L1.
Thank you 
I’ll look it up.
well not relevant here…but u will also find a “kink” model(read graph) in oligopoly section of microeconomics…
Comment edited.No more “Thank you” because you exlicitly asked me to not reply to your comments ever on AF (If I got that correct 
). Sorry, if I hurt your sentiments by replying back. Sometimes, I wanna kick myself for being so humble 
Listen you were posting nonsense and unwanted things on my post,as a result i had to ask you to refrain from posting again.I will have no problems if you can post some thing “relevant” to the topic.I read this post of yours and found it to be a “good” tool to fresh up certain concepts."Kink model"is very important LOS in eco section.
and i donot need you to thank me at all.