Train increased the stake in the club held by his Finsbury Growth & Income trust from 2.6 million shares to 2.84 million or 3% worth £2.1 million at a share price of 74p.
Across his range of three investment funds, Train, co-founder and director of investment house Lindsell Train, holds more than 7% of club shares.
Canaccord Genuity initiated coverage on Celtic last year with a buy recommendation and a target price of 103p.
Speaking to Citywire in 2011, Train said that he considered the-then valuation of Celtic at £35 million a significant discount to the embedded value of the business. Speaking more recently, financial analysts have estimated the enterprise value of the club as above £50 million.
In the second half of 2013 Celtic reported profit of £21.3 million compared to £14.9 million in 2012.