On the one hand nerd can definitely still be an insult. Consider this clip of the Philadelphia Flyers player Travis Konecny chirping the Pittsburgh Penguins player Evgeni Malkin last year (the relevant bit comes around 38 seconds in):
(I can neither confirm nor deny whether I like watching Penguins players getting chirped)
Konecny clearly uses nerd as an insult. Yes, he qualifies it by saying “ya fucking nerd,” but he also calls Malkin just “you nerd”. Now, despite what you may think of Penguins players, Malkin is probably the opposite of the traditional definition of a “nerd” – he’s an elite athlete. (But maybe he’s a hockey nerd???)
On the other hand, might not be using nerd to be an insult much anymore. Earlier this year, Dr. Lisa Davidson tweeted about whether geek and nerd are humblebrags.
This led to some discussion which you should check out. The idea is that maybe the word nerd has changed from something that is definitely negative into something that is maybe positive. Before you confirm your intuitions, keep reading. I thought checking a corpus would be good to answer this question (you know, because I’m a corpus linguist). I decided to check the iWeb corpus because it is unedited and so should give us an idea of how nerd is used “in the wild”. The iWeb corpus is very large (14 billion words) and contains language from websites in 6 English-speaking countries (US, Canada, Ireland, the UK, Australia, and New Zealand) from 2017. There are 38,554 instances of nerd in the corpus. So I took a random sample of 500. Go here to automatically search for “nerd” on the iWeb corpus, and here for an overview of the corpus (PDF).
Here is my sample of nerd instances in the iWeb corpus as an .xlsx file. (The corpus sample only gave me 499 for some reason, so I went and grabbed the first result in the listings to make my list 500.)