Is there a valid basis for Anti-Semitism?
No, there isn't.
To answer a different question that you've asked in this thread,
why do you think that the success is inspite of victimization
Natural selection (both in terms of habits in how they raised children and perhaps certain dispositions) is quite literally the reason that there certainly has been a reality that the most tough (primarily) and quick-witted (secondarily) survived the several persecutions of their ethnicity.
Due to the persecution, not only being fast-thinking is selected in favour of but being 'tough and loyal' in themselves are. If you don't help out others in effective 'tit for tat' trades, you would over time end up isolated and easily persecuted (perhaps violently or at least financially in a glass ceiling for your career prospects).
Do note, however, that quality of childhood mental stimulation and emphasis on education are present in Jewish culture. The reason a persecuted ethnicity may end up underperforming tends to be a combination of lack of opportunity meeting lack of education, this tends to lead to children who have lack of nutrition for brain development and lack of external stimuli to make them want to push their intellect, as opposed to their athleticism or 'grit'.
It's the 'toughness' that always is primarily selected in favour of with the persecuted, you will find they're consistently extremely tough characters mentally many generations down the line because you had to be to survive, if you were unfortunate enough to have a disposition towards depression and anxiety and it crippled your performance and stamina, you either ended up dead or totally pushed to deep poverty.
What you can say 'toughness' is is perhaps the tendency to react to a situation of distress with ire, as opposed to sadness or anxiety. Those that found hardship very motivating and are the type of people whose genes and minds led to them being motivated to 'avoid negative outcome' more than 'seek positive outcome' probably found life more bearable and reproduced, raised tough children etc. Those that were sensitive, responded more to motivation based on 'seeking positive outcome' or approached anxiety with a 'let's chill out' approach tended to remain single or have an only child and invest entirely in them, just due to the stress and way their personality type didn't end up able to flourish given the circumstances.
I read this post over several times to make sure I carefully worded each part to not get twisted to make me seem in any shape or form racist or bigoted. If anyone feels offended personally, feel free to let me know why. I am trying to explain in a 100% non-bigoted way how and why a persecuted ethnicity ends up particularly resourceful more often than not, if given the opportunity to.