Percentages are always a game of how you say it.
Given Donald's numbers:
Former number of shares: 451,902 (if this isn't what the number represents then all calculations below are wrong.)
Current number of shares: 701,902
You have an increase of 250,000 shares in the holdings.
250,000/451,902 = .5532 = 55.32%
You can claim the institution increased their holdings by 55% and now hold 155% of the amount they did before the purchase.
However, the number Donald gave does NOT represent the percentage associated with the number of shares. It represents the percentage increase in the value of the shares.
That percentage includes the appreciation of the value of their existing shares also. So the 180% is made up of the increase in the number of shares and the increase in the price of each of those shares.
Bottom line: Both of you are correct.