Yes, the best part of summer isn't the part where the big swinging dick MDs head off for a couple weeks break, although that comes pretty close. The best part of summer is internship season, where it signals a reset of the recruitment cycle where you see an injection of new blood into the system, because post summer is typically when the newly minted Analysts and Associates fresh out of school and banking training programs hit the desk full time.
I've always been a big believer in internships over an extended period of time (10 weeks is sufficient) for both the intern and the corporate entity extending the internship, to see if someone has the potential to undertake the real deal once he leave school. The intern on the other hand, benefits to see if the "real thing" matches up to what he perceived the industry to be prior to joining. There is only so much conjecture one can think up about what it's like to crank for more than 90 hours a week for a couple of weeks straight, instead of living through that phase.
Summer internships bring about some other positive externalities to the organisation, as the lowest men on the totem pole (typically the rising first year Analysts) would have to guide the interns in their day to day job, which provides an integral set of skills that will be useful as they climb through the rungs. Also, the vitality and life force that the summer interns provide is always fun, given the numerous mandatory social events that get scheduled over the course of summer.
This summer looks pretty bleak - markets in SEA are getting pummeled, and the negative global events such as Brexit wouldn't be conducive to conducting the traditional investment banking activities. Investment banks have already or are probably in the process of cutting headcount, something which would probably be expedited if the markets do not trend up soon after the latest Brexit blow. That probably means lower headcount for full time jobs that will be offered at the end of each summer internship, which makes the competition even more vicious.
Having been a summer intern in the traditional Investment Banking Department (where people sell stocks and peddle mergers and acquisitions advice) more than half a decade ago, I find the traits of having a good attitude, being generally being grounded and getting along well with both your peers and the junior bankers to be quintessential in securing a full time job. No one is expecting the summer interns to be able to execute their jobs to perfection, but the young padawan learners must show the potential to be able to do so one day (and that day is always always sooner than they think). Oh yes, and if the group drinks, having the ability to do a few shots without getting pissed drunk helps as well. And if you don't have that ability, in some groups I know getting wasted is always way better than shirking drinks. Yes, very very strange, I know.
I'm sure summer will be fun. Lighten up all you Brexit moaners. It probably doesn't affect you as much as you think. Even if it does, recite the serenity prayer, because even if you are David Cameron himself, you'll find that you have absolutely no control over the effects of Brexit. And wish well to the Summer Analyst and Associate classes of 2016. Good luck guys!