債券問題？讀國際學校

讀國際學校是否一定或多數要買債券呢？而那些債券會 投資邊一方面？是否虧損多過盈利？請問大家有沒有經驗呢？
市場價格：例如：ＹＥＷ　ＣＨＵＮＧ　２０萬　退學後要二個月才可以取回＄
美國國際學校：？
加拿大國際學校：？
等等．．．．．．？
GSIS-DEBENTURE VALUE
The value of a debenture is currently HKD 120,000. The school reserves the right to change the value
of its debentures without any prior notice.
CIS School fee is HK$105,000 / annum
Debenture HK$75,000

GSIS School fee is HK$85,460 / annum
Debenture HK$120,000

ESF School fee is HK$51,500 / annum
No debenture