Chart 1: FBMKLCI's daily chart as at June 28, 2018_12.30pm (Source: Shareinvestor.com)
The drop in FBMKLCI has brought the index to the line connecting the low since 2010 (denoted as "AB"). The support from that line should be at 1650. That coincides with the horizontal line too. Thus I believe FBMKLCI should have a decent chance of at least a technical rebound from this level. I would not be surprised if this level may stop the current market sell-off.
Chart 2: FBMKLCI's monthly chart as at June 28, 2018_12.30pm (Source: Shareinvestor.com)
You see the composite charts of FBM70, FBMSCAP, FBMACE & FBMFLG are showing the 2nd & 3rd liner stocks; Ace Market stocks; and the fledgling stocks have not dropped as badly as the blue chip stocks. The drop in blue chips is due to selling by foreign fund managers due to many market fears, notably trade war waged by the U.S. against her major trading partners.
Chart 3: FBM70, FBMSCAP, FBMACE and FBMFLG's daily chart as at June 28, 2018_12.30pm (Source: Shareinvestor.com)
It is hard to advise on how you should position yourself in a weak market. How much you should hold or buy in a falling market is determined by your own market outlook, experience and pain tolerance. If the market decline is giving you sleepless nights, you should consider reducing your portfolio to a level that allows you to sleep better. On the other hand, you may find share prices are trading at fairly attractive level and you feel like buying in the market now. My advice is to buy slowly so that you won't be joining those who are having sleepless nights. Good luck.