Sun in fifth house is in the house of his friend Jupiter. Although this place is great for matters of politics, theater, fame and popularity it may not bode well for other matters of the fifth house like stock market trading, children and gambling. Fifth house also rules over knowledge and intelligence. And the bright and cheerful Sun gives a bright intellect and sharp memory along with sound knowledge. 

     According to B. V. Raman, those with Sun in fifth house have short life and many a times suffer from heart diseases. Also he/she could have difficulty in conceiving children. There could be especially troubles with conceiving progeny if Sun is aspected or co-tenant with other malefics like Saturn, Ketu, Mars and Rahu. While Jupiter and Moon as co-tenants could give healthy and beautiful children. Jupiter and Moon as co-tenants gives better results for matters of stock market and positive fame. While placement of Sun along with malefics, aspect by malefics or placement in enemy sign could give negative fame, Losses in stock markets and gambling and also troubles acquiring knowledge.  Sun in fifth house especially in a favorable sign and with friendly planets could signal long lasting fame. Many great actors, politicians, musicians and sportsperson who have become immortal in public memory have Sun in the fifth house. 

     Sun in fifth house is not a bad placement at all. If there are problems with conceiving children then natives should pray to Lord Ganesha. If there is negative publicity then one should try and keep a low profile and also pray to Lord Vishnu. 

References:

Raman, Bangalore Venkata. How to Judge a Horoscope. Delhi: Motilal Banarsidass, 2014. Print.