Hop until your legs come off
think of it this way: let's say your pay is 35k/yr, so 2900$ per month.
So you started in January. It's June now and you've decided to check out the job market, sent out some applications. Now here is what could happen:
1) You get no replies/no offers, be it because employers think "why is he hopping already?" or they just didn't like your face or you don't have qualifications. It doesn't matter, you have gained nothing, but you've also lost nothing
2) You get an offer for 45k/yr, 3750 a month, a 30% increase. You take it starting July, meaning you would've made 5100$ more for this year.
3) You don't take the offer or you never applied because you thought "I have to stay at this job for at least a year or it'll look bad". So in January next your you take this same offer, and you would've effectively "lost" 5100$ opportunity wages
4) You don't take the offer or you never applied. In January next year you get a better offer of actually 48k/yr, 4000$ monthly. Great, the waiting paid out right? Wrong, you'll actually take years of that higher wage to off-set the lost opportunity wages
Basically,
AS LONG AS IT WORKS, you should switch jobs and keeps taking the wage increases, and you should do it as long as you improve your position and it works. Basically, the most important point here is the "as long as it works", not the actual opinions of anyone who says it looks bad or whatever. You try it, if it works you take the opportunity, and if it doesn't you haven't lost anything and still have the option to stay at the company 6-12-18-however many months longer and retrying again later.
Let me just go a bit turbo-autistic on you to show you what I mean
So you basically need 2 years to off-set the lost opportunity wages of changing earlier. And if at any point during that 3 year time spin you change again and improve your wage again, the gap keep widening and you start needing ever more years and ever bigger wage increases to catch up. The "risk" of being a job hopper is a self-limiting belief that you're giving yourself. For any given application, you got a random chance of the person simply not liking you. If it's not nit picking about the job hopping, then it'll be your college that's not good enough or whatever. Unless you're working in some hardcore small niche industry/town, people overvalue and overhype the "word gets around" thing waaaay too much. You've got to remember that corporations aren't live beings, corporations don't talk to each other. Live humans who comprise those corporations do, and for "word to get around" you'd need to have certain live humans who know each other at both corps in both the right positions so they can exchange information. Otherwise, your actions simply fade away